NSArray Class Reference

Inherits from
Conforms to
Framework
/System/Library/Frameworks/Foundation.framework
Availability
Available in iOS 2.0 and later.
Companion guide
Declared in
NSArray.h
NSKeyValueCoding.h
NSKeyValueObserving.h
NSPathUtilities.h
NSPredicate.h
NSSortDescriptor.h
Related sample code

Overview

NSArray and its subclass NSMutableArray manage ordered collections of objects called arrays. NSArray creates static arrays, and NSMutableArray creates dynamic arrays. You can use arrays when you need an ordered collection of objects.

NSArray is “toll-free bridged” with its Core Foundation counterpart, CFArrayRef. See “Toll-Free Bridging” for more information on toll-free bridging.

Subclassing Notes

There is typically little reason to subclass NSArray. The class does well what it is designed to do—maintain an ordered collection of objects. But there are situations where a custom NSArray object might come in handy. Here are a few possibilities:

Methods to Override

Any subclass of NSArray must override the primitive instance methods count and objectAtIndex:. These methods must operate on the backing store that you provide for the elements of the collection. For this backing store you can use a static array, a standard NSArray object, or some other data type or mechanism. You may also choose to override, partially or fully, any other NSArray method for which you want to provide an alternative implementation.

You might want to implement an initializer for your subclass that is suited to the backing store that the subclass is managing. If you do, your initializer must invoke one of the designated initializers of the NSArray class, either init or initWithObjects:count:. The NSArray class adopts the NSCopying, NSMutableCopying, and NSCoding protocols; if you want instances of your own custom subclass created from copying or coding, override the methods in these protocols.

Remember that NSArray is the public interface for a class cluster and what this entails for your subclass. You must provide the storage for your subclass and implement the primitive methods that directly act on that storage.

Alternatives to Subclassing

Before making a custom class of NSArray, investigate NSPointerArray and the corresponding Core Foundation type, CFArray Reference. Because NSArray and CFArray are “toll-free bridged,” you can substitute a CFArray object for a NSArray object in your code (with appropriate casting). Although they are corresponding types, CFArray and NSArray do not have identical interfaces or implementations, and you can sometimes do things with CFArray that you cannot easily do with NSArray. For example, CFArray provides a set of callbacks, some of which are for implementing custom retain-release behavior. If you specify NULL implementations for these callbacks, you can easily get a non-retaining array.

If the behavior you want to add supplements that of the existing class, you could write a category on NSArray. Keep in mind, however, that this category will be in effect for all instances of NSArray that you use, and this might have unintended consequences. Alternatively, you could use composition to achieve the desired behavior.

Tasks

Creating an Array

Initializing an Array

Querying an Array

Finding Objects in an Array

Sending Messages to Elements

Comparing Arrays

Deriving New Arrays

Sorting

Working with String Elements

Creating a Description

Collecting Paths

Key-Value Observing

Key-Value Coding

Class Methods

array

Creates and returns an empty array.

+ (instancetype)array
Return Value

An empty array.

Discussion

This method is used by mutable subclasses of NSArray.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

arrayWithArray:

Creates and returns an array containing the objects in another given array.

+ (instancetype)arrayWithArray:(NSArray *)anArray
Parameters
anArray

An array.

Return Value

An array containing the objects in anArray.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

arrayWithContentsOfFile:

Creates and returns an array containing the contents of the file specified by a given path.

+ (id)arrayWithContentsOfFile:(NSString *)aPath
Parameters
aPath

The path to a file containing a string representation of an array produced by the writeToFile:atomically: method.

Return Value

An array containing the contents of the file specified by aPath. Returns nil if the file can’t be opened or if the contents of the file can’t be parsed into an array.

Discussion

The array representation in the file identified by aPath must contain only property list objects (NSString, NSData, NSDate, NSNumber, NSArray, or NSDictionary objects). For more details, see Property List Programming Guide. The objects contained by this array are immutable, even if the array is mutable.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

arrayWithContentsOfURL:

Creates and returns an array containing the contents specified by a given URL.

+ (id)arrayWithContentsOfURL:(NSURL *)aURL
Parameters
aURL

The location of a file containing a string representation of an array produced by the writeToURL:atomically: method.

Return Value

An array containing the contents specified by aURL. Returns nil if the location can’t be opened or if the contents of the location can’t be parsed into an array.

Discussion

The array representation at the location identified by aURL must contain only property list objects (NSString, NSData, NSArray, or NSDictionary objects). The objects contained by this array are immutable, even if the array is mutable.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

arrayWithObject:

Creates and returns an array containing a given object.

+ (instancetype)arrayWithObject:(id)anObject
Parameters
anObject

An object.

Return Value

An array containing the single element anObject.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

arrayWithObjects:

Creates and returns an array containing the objects in the argument list.

+ (instancetype)arrayWithObjects:(id)firstObj,,...
Parameters
firstObj, ...

A comma-separated list of objects ending with nil.

Return Value

An array containing the objects in the argument list.

Discussion

This code example creates an array containing three different types of element:

NSArray *myArray;
NSDate *aDate = [NSDate distantFuture];
NSValue *aValue = [NSNumber numberWithInt:5];
NSString *aString = @"a string";
 
myArray = [NSArray arrayWithObjects:aDate, aValue, aString, nil];
Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

arrayWithObjects:count:

Creates and returns an array that includes a given number of objects from a given C array.

+ (instancetype)arrayWithObjects:(const id [])objects count:(NSUInteger)count
Parameters
objects

A C array of objects.

count

The number of values from the objects C array to include in the new array. This number will be the count of the new array—it must not be negative or greater than the number of elements in objects.

Return Value

A new array including the first count objects from objects.

Discussion

Elements are added to the new array in the same order they appear in objects, up to but not including index count. For example:

NSString *strings[3];
strings[0] = @"First";
strings[1] = @"Second";
strings[2] = @"Third";
 
NSArray *stringsArray = [NSArray arrayWithObjects:strings count:2];
// strings array contains { @"First", @"Second" }
Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

Instance Methods

addObserver:forKeyPath:options:context:

Raises an exception.

- (void)addObserver:(NSObject *)observer forKeyPath:(NSString *)keyPath options:(NSKeyValueObservingOptions)options context:(void *)context
Parameters
observer

The object to register for KVO notifications. The observer must implement the key-value observing method observeValueForKeyPath:ofObject:change:context:.

keyPath

The key path, relative to the array, of the property to observe. This value must not be nil.

options

A combination of NSKeyValueObservingOptions values that specifies what is included in observation notifications.

context

Arbitrary data that is passed to observer in observeValueForKeyPath:ofObject:change:context:.

Special Considerations

NSArray objects are not observable, so this method raises an exception when invoked on an NSArray object. Instead of observing an array, observe the to-many relationship for which the array is the collection of related objects.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSKeyValueObserving.h

addObserver:toObjectsAtIndexes:forKeyPath:options:context:

Registers an observer to receive key value observer notifications for the specified key-path relative to the objects at the indexes.

- (void)addObserver:(NSObject *)anObserver toObjectsAtIndexes:(NSIndexSet *)indexes forKeyPath:(NSString *)keyPath options:(NSKeyValueObservingOptions)options context:(void *)context
Parameters
anObserver

The observer.

indexes

The index set.

keyPath

The key path, relative to the array, to be observed.

options

The options to be included in the notification.

context

The context passed to the notifications.

Discussion

The options determine what is included in the notifications, and the context is passed in the notifications.

This is not merely a convenience method; invoking this method is potentially much faster than repeatedly invoking addObserver:forKeyPath:options:context:.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSKeyValueObserving.h

arrayByAddingObject:

Returns a new array that is a copy of the receiving array with a given object added to the end.

- (NSArray *)arrayByAddingObject:(id)anObject
Parameters
anObject

An object.

Return Value

A new array that is a copy of the receiving array with anObject added to the end.

Discussion

If anObject is nil, an NSInvalidArgumentException is raised.

Availability
  • Available in iOS 2.0 and later.
See Also
Declared In
NSArray.h

arrayByAddingObjectsFromArray:

Returns a new array that is a copy of the receiving array with the objects contained in another array added to the end.

- (NSArray *)arrayByAddingObjectsFromArray:(NSArray *)otherArray
Parameters
otherArray

An array.

Return Value

A new array that is a copy of the receiving array with the objects contained in otherArray added to the end.

Availability
  • Available in iOS 2.0 and later.
See Also
Related Sample Code
Declared In
NSArray.h

componentsJoinedByString:

Constructs and returns an NSString object that is the result of interposing a given separator between the elements of the array.

- (NSString *)componentsJoinedByString:(NSString *)separator
Parameters
separator

The string to interpose between the elements of the array.

Return Value

An NSString object that is the result of interposing separator between the elements of the array. If the array has no elements, returns an NSString object representing an empty string.

Discussion

For example, this code excerpt writes "here be dragons" to the console:

NSArray *pathArray = [NSArray arrayWithObjects:@"here", @"be", @"dragons", nil];
NSLog(@"%@",[pathArray componentsJoinedByString:@" "]);
Special Considerations

Each element in the array must handle description.

Availability
  • Available in iOS 2.0 and later.
See Also
Declared In
NSArray.h

containsObject:

Returns a Boolean value that indicates whether a given object is present in the array.

- (BOOL)containsObject:(id)anObject
Parameters
anObject

An object.

Return Value

YES if anObject is present in the array, otherwise NO.

Discussion

This method determines whether anObject is present in the array by sending an isEqual: message to each of the array’s objects (and passing anObject as the parameter to each isEqual: message).

Availability
  • Available in iOS 2.0 and later.
Related Sample Code
Declared In
NSArray.h

count

Returns the number of objects currently in the array.

- (NSUInteger)count
Return Value

The number of objects currently in the array.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

description

Returns a string that represents the contents of the array, formatted as a property list.

- (NSString *)description
Return Value

A string that represents the contents of the array, formatted as a property list.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

descriptionWithLocale:

Returns a string that represents the contents of the array, formatted as a property list.

- (NSString *)descriptionWithLocale:(id)locale
Parameters
locale

An NSLocale object or an NSDictionary object that specifies options used for formatting each of the array’s elements (where recognized). Specify nil if you don’t want the elements formatted.

Return Value

A string that represents the contents of the array, formatted as a property list.

Discussion

For a description of how locale is applied to each element in the receiving array, see descriptionWithLocale:indent:.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

descriptionWithLocale:indent:

Returns a string that represents the contents of the array, formatted as a property list.

- (NSString *)descriptionWithLocale:(id)locale indent:(NSUInteger)level
Parameters
locale

An NSLocale object or an NSDictionary object that specifies options used for formatting each of the array’s elements (where recognized). Specify nil if you don’t want the elements formatted.

level

A level of indent, to make the output more readable: set level to 0 to use four spaces to indent, or 1 to indent the output with a tab character.

Return Value

A string that represents the contents of the array, formatted as a property list.

Discussion

The returned NSString object contains the string representations of each of the array’s elements, in order, from first to last. To obtain the string representation of a given element, descriptionWithLocale:indent: proceeds as follows:

  • If the element is an NSString object, it is used as is.

  • If the element responds to descriptionWithLocale:indent:, that method is invoked to obtain the element’s string representation.

  • If the element responds to descriptionWithLocale:, that method is invoked to obtain the element’s string representation.

  • If none of the above conditions is met, the element’s string representation is obtained by invoking its description method.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

enumerateObjectsAtIndexes:options:usingBlock:

Executes a given block using the objects in the array at the specified indexes.

- (void)enumerateObjectsAtIndexes:(NSIndexSet *)indexSet options:(NSEnumerationOptions)opts usingBlock:(void (^)(id obj, NSUInteger idx, BOOL *stop))block
Parameters
indexSet

The indexes of the objects over which to enumerate.

opts

A bit mask that specifies the options for the enumeration (whether it should be performed concurrently and whether it should be performed in reverse order).

block

The block to apply to elements in the array.

The block takes three arguments:

obj

The element in the array.

idx

The index of the element in the array.

stop

A reference to a Boolean value. The block can set the value to YES to stop further processing of the array. The stop argument is an out-only argument. You should only ever set this Boolean to YES within the Block.

Discussion

By default, the enumeration starts with the first object and continues serially through the array to the last element specified by indexSet. You can specify NSEnumerationConcurrent and/or NSEnumerationReverse as enumeration options to modify this behavior.

This method executes synchronously.

Availability
  • Available in iOS 4.0 and later.
Declared In
NSArray.h

enumerateObjectsUsingBlock:

Executes a given block using each object in the array, starting with the first object and continuing through the array to the last object.

- (void)enumerateObjectsUsingBlock:(void (^)(id obj, NSUInteger idx, BOOL *stop))block
Parameters
block

The block to apply to elements in the array.

The block takes three arguments:

obj

The element in the array.

idx

The index of the element in the array.

stop

A reference to a Boolean value. The block can set the value to YES to stop further processing of the array. The stop argument is an out-only argument. You should only ever set this Boolean to YES within the Block.

Discussion

If the Block parameter is nil this method will raise an exception.

This method executes synchronously.

Availability
  • Available in iOS 4.0 and later.
Related Sample Code
Declared In
NSArray.h

enumerateObjectsWithOptions:usingBlock:

Executes a given block using each object in the array.

- (void)enumerateObjectsWithOptions:(NSEnumerationOptions)opts usingBlock:(void (^)(id obj, NSUInteger idx, BOOL *stop))block
Parameters
opts

A bit mask that specifies the options for the enumeration (whether it should be performed concurrently and whether it should be performed in reverse order).

block

The block to apply to elements in the array.

The block takes three arguments:

obj

The element in the array.

idx

The index of the element in the array.

stop

A reference to a Boolean value. The block can set the value to YES to stop further processing of the array. The stop argument is an out-only argument. You should only ever set this Boolean to YES within the Block.

Discussion

By default, the enumeration starts with the first object and continues serially through the array to the last object. You can specify NSEnumerationConcurrent and/or NSEnumerationReverse as enumeration options to modify this behavior.

This method executes synchronously.

Availability
  • Available in iOS 4.0 and later.
Declared In
NSArray.h

filteredArrayUsingPredicate:

Evaluates a given predicate against each object in the receiving array and returns a new array containing the objects for which the predicate returns true.

- (NSArray *)filteredArrayUsingPredicate:(NSPredicate *)predicate
Parameters
predicate

The predicate against which to evaluate the receiving array’s elements.

Return Value

A new array containing the objects in the receiving array for which predicate returns true.

Discussion

For more details, see Predicate Programming Guide.

Availability
  • Available in iOS 3.0 and later.
Related Sample Code
Declared In
NSPredicate.h

firstObject

Returns the first object in the array.

- (id)firstObject
Return Value

The first object in the array. If the array is empty, returns nil.

Availability
  • Available in iOS 4.0 and later.
Declared In
NSArray.h

firstObjectCommonWithArray:

Returns the first object contained in the receiving array that’s equal to an object in another given array.

- (id)firstObjectCommonWithArray:(NSArray *)otherArray
Parameters
otherArray

An array.

Return Value

Returns the first object contained in the receiving array that’s equal to an object in otherArray. If no such object is found, returns nil.

Discussion

This method uses isEqual: to check for object equality.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

getObjects:range:

Copies the objects contained in the array that fall within the specified range to aBuffer.

- (void)getObjects:(id __unsafe_unretained [])objects range:(NSRange)range
Parameters
aBuffer

A C array of objects of size at least the length of the range specified by aRange.

aRange

A range within the bounds of the array.

If the location plus the length of the range is greater than the count of the array, this method raises an NSRangeException.

Discussion

The method copies into aBuffer the objects in the array in the range specified by aRange; the size of the buffer must therefore be at least the length of the range multiplied by the size of an object reference, as shown in the following example (this is solely for illustration—you should typically not create a buffer simply to iterate over the contents of an array):

NSArray *mArray = // an array with at least six elements...;
id *objects;
 
NSRange range = NSMakeRange(2, 4);
objects = malloc(sizeof(id) * range.length);
 
[mArray getObjects:objects range:range];
 
for (i = 0; i < range.length; i++) {
    NSLog(@"objects: %@", objects[i]);
}
free(objects);
Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

indexesOfObjectsAtIndexes:options:passingTest:

Returns the indexes, from a given set of indexes, of objects in the array that pass a test in a given Block for a given set of enumeration options.

- (NSIndexSet *)indexesOfObjectsAtIndexes:(NSIndexSet *)indexSet options:(NSEnumerationOptions)opts passingTest:(BOOL (^)(id obj, NSUInteger idx, BOOL *stop))predicate
Parameters
indexSet

The indexes of the objects over which to enumerate.

opts

A bit mask that specifies the options for the enumeration (whether it should be performed concurrently and whether it should be performed in reverse order).

predicate

The block to apply to elements in the array.

The block takes three arguments:

obj

The element in the array.

idx

The index of the element in the array.

stop

A reference to a Boolean value. The block can set the value to YES to stop further processing of the array. The stop argument is an out-only argument. You should only ever set this Boolean to YES within the Block.

The Block returns a Boolean value that indicates whether obj passed the test.

Return Value

The indexes whose corresponding values in the array pass the test specified by predicate. If no objects in the array pass the test, returns an empty index set.

Discussion

By default, the enumeration starts with the first object and continues serially through the array to the last element specified by indexSet. You can specify NSEnumerationConcurrent and/or NSEnumerationReverse as enumeration options to modify this behavior.

Availability
  • Available in iOS 4.0 and later.
Declared In
NSArray.h

indexesOfObjectsPassingTest:

Returns the indexes of objects in the array that pass a test in a given Block.

- (NSIndexSet *)indexesOfObjectsPassingTest:(BOOL (^)(id obj, NSUInteger idx, BOOL *stop))predicate
Parameters
predicate

The block to apply to elements in the array.

The block takes three arguments:

obj

The element in the array.

idx

The index of the element in the array.

stop

A reference to a Boolean value. The block can set the value to YES to stop further processing of the array. The stop argument is an out-only argument. You should only ever set this Boolean to YES within the Block.

The Block returns a Boolean value that indicates whether obj passed the test.

Return Value

The indexes whose corresponding values in the array pass the test specified by predicate. If no objects in the array pass the test, returns an empty index set.

Availability
  • Available in iOS 4.0 and later.
Declared In
NSArray.h

indexesOfObjectsWithOptions:passingTest:

Returns the indexes of objects in the array that pass a test in a given Block for a given set of enumeration options.

- (NSIndexSet *)indexesOfObjectsWithOptions:(NSEnumerationOptions)opts passingTest:(BOOL (^)(id obj, NSUInteger idx, BOOL *stop))predicate
Parameters
opts

A bit mask that specifies the options for the enumeration (whether it should be performed concurrently and whether it should be performed in reverse order).

predicate

The block to apply to elements in the array.

The block takes three arguments:

obj

The element in the array.

idx

The index of the element in the array.

stop

A reference to a Boolean value. The block can set the value to YES to stop further processing of the array. The stop argument is an out-only argument. You should only ever set this Boolean to YES within the Block.

The Block returns a Boolean value that indicates whether obj passed the test.

Return Value

The indexes whose corresponding values in the array pass the test specified by predicate. If no objects in the array pass the test, returns an empty index set.

Discussion

By default, the enumeration starts with the first object and continues serially through the array to the last object. You can specify NSEnumerationConcurrent and/or NSEnumerationReverse as enumeration options to modify this behavior.

Availability
  • Available in iOS 4.0 and later.
Declared In
NSArray.h

indexOfObject:

Returns the lowest index whose corresponding array value is equal to a given object.

- (NSUInteger)indexOfObject:(id)anObject
Parameters
anObject

An object.

Return Value

The lowest index whose corresponding array value is equal to anObject. If none of the objects in the array is equal to anObject, returns NSNotFound.

Discussion

Starting at index 0, each element of the array is sent an isEqual: message until a match is found or the end of the array is reached. This method passes the anObject parameter to each isEqual: message. Objects are considered equal if isEqual: (declared in the NSObject protocol) returns YES.

Availability
  • Available in iOS 2.0 and later.
Related Sample Code
Declared In
NSArray.h

indexOfObject:inRange:

Returns the lowest index within a specified range whose corresponding array value is equal to a given object .

- (NSUInteger)indexOfObject:(id)anObject inRange:(NSRange)range
Parameters
anObject

An object.

range

The range of indexes in the array within which to search for anObject.

Return Value

The lowest index within range whose corresponding array value is equal to anObject. If none of the objects within range is equal to anObject, returns NSNotFound.

Discussion

Starting at range.location, each element of the array is sent an isEqual: message until a match is found or the end of the range is reached. This method passes the anObject parameter to each isEqual: message. Objects are considered equal if isEqual: returns YES.

This method raises an NSRangeException exception if the range parameter represents a range that doesn’t exist in the array.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

indexOfObject:inSortedRange:options:usingComparator:

Returns the index, within a specified range, of an object compared with elements in the array using a given NSComparator block.

- (NSUInteger)indexOfObject:(id)obj inSortedRange:(NSRange)r options:(NSBinarySearchingOptions)opts usingComparator:(NSComparator)cmp
Parameters
obj

An object for which to search in the array.

If this value is nil, throws an NSInvalidArgumentException.

r

The range within the array to search for obj.

If r exceeds the bounds of the array (if the location plus length of the range is greater than the count of the array), throws an NSRangeException.

opts

Options for the search. For possible values, see “NSBinarySearchingOptions.”

If you specify both NSBinarySearchingFirstEqual and NSBinarySearchingLastEqual, throws an NSInvalidArgumentException.

cmp

A comparator block used to compare the object obj with elements in the array.

If this value is NULL, throws an NSInvalidArgumentException.

Return Value

If the NSBinarySearchingInsertionIndex option is not specified:

If the NSBinarySearchingInsertionIndex option is specified, returns the index at which you should insert obj in order to maintain a sorted array:

  • If the obj is found and neither NSBinarySearchingFirstEqual nor NSBinarySearchingLastEqual is specified, returns any equal or one larger index than any matching object’s index.

  • If the NSBinarySearchingFirstEqual option is also specified, returns the lowest index of equal objects.

  • If the NSBinarySearchingLastEqual option is also specified, returns the highest index of equal objects.

  • If the object is not found, returns the index of the least greater object, or the index at the end of the array if the object is larger than all other elements.

Special Considerations

The elements in the array must have already been sorted using the comparator cmp. If the array is not sorted, the result is undefined.

Availability
  • Available in iOS 4.0 and later.
Declared In
NSArray.h

indexOfObjectAtIndexes:options:passingTest:

Returns the index, from a given set of indexes, of the first object in the array that passes a test in a given Block for a given set of enumeration options.

- (NSUInteger)indexOfObjectAtIndexes:(NSIndexSet *)indexSet options:(NSEnumerationOptions)opts passingTest:(BOOL (^)(id obj, NSUInteger idx, BOOL *stop))predicate
Parameters
indexSet

The indexes of the objects over which to enumerate.

opts

A bit mask that specifies the options for the enumeration (whether it should be performed concurrently and whether it should be performed in reverse order).

predicate

The block to apply to elements in the array.

The block takes three arguments:

obj

The element in the array.

idx

The index of the element in the array.

stop

A reference to a Boolean value. The block can set the value to YES to stop further processing of the array. The stop argument is an out-only argument. You should only ever set this Boolean to YES within the Block.

The Block returns a Boolean value that indicates whether obj passed the test.

Return Value

The lowest index whose corresponding value in the array passes the test specified by predicate. If no objects in the array pass the test, returns NSNotFound.

Discussion

By default, the enumeration starts with the first object and continues serially through the array to the last element specified by indexSet. You can specify NSEnumerationConcurrent and/or NSEnumerationReverse as enumeration options to modify this behavior.

Availability
  • Available in iOS 4.0 and later.
Declared In
NSArray.h

indexOfObjectIdenticalTo:

Returns the lowest index whose corresponding array value is identical to a given object.

- (NSUInteger)indexOfObjectIdenticalTo:(id)anObject
Parameters
anObject

An object.

Return Value

The lowest index whose corresponding array value is identical to anObject. If none of the objects in the array is identical to anObject, returns NSNotFound.

Discussion

Objects are considered identical if their object addresses are the same.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

indexOfObjectIdenticalTo:inRange:

Returns the lowest index within a specified range whose corresponding array value is equal to a given object .

- (NSUInteger)indexOfObjectIdenticalTo:(id)anObject inRange:(NSRange)range
Parameters
anObject

An object.

range

The range of indexes in the array within which to search for anObject.

Return Value

The lowest index within range whose corresponding array value is identical to anObject. If none of the objects within range is identical to anObject, returns NSNotFound.

Discussion

Objects are considered identical if their object addresses are the same.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

indexOfObjectPassingTest:

Returns the index of the first object in the array that passes a test in a given Block.

- (NSUInteger)indexOfObjectPassingTest:(BOOL (^)(id obj, NSUInteger idx, BOOL *stop))predicate
Parameters
predicate

The block to apply to elements in the array.

The block takes three arguments:

obj

The element in the array.

idx

The index of the element in the array.

stop

A reference to a Boolean value. The block can set the value to YES to stop further processing of the array. The stop argument is an out-only argument. You should only ever set this Boolean to YES within the Block.

The Block returns a Boolean value that indicates whether obj passed the test. Returning YES will stop further processing of the array.

Return Value

The lowest index whose corresponding value in the array passes the test specified by predicate. If no objects in the array pass the test, returns NSNotFound.

Discussion

If the Block parameter is nil this method will raise an exception.

Availability
  • Available in iOS 4.0 and later.
Declared In
NSArray.h

indexOfObjectWithOptions:passingTest:

Returns the index of an object in the array that passes a test in a given Block for a given set of enumeration options.

- (NSUInteger)indexOfObjectWithOptions:(NSEnumerationOptions)opts passingTest:(BOOL (^)(id obj, NSUInteger idx, BOOL *stop))predicate
Parameters
opts

A bit mask that specifies the options for the enumeration (whether it should be performed concurrently and whether it should be performed in reverse order).

predicate

The block to apply to elements in the array.

The block takes three arguments:

obj

The element in the array.

idx

The index of the element in the array.

stop

A reference to a Boolean value. The block can set the value to YES to stop further processing of the array. The stop argument is an out-only argument. You should only ever set this Boolean to YES within the Block.

The Block returns a Boolean value that indicates whether obj passed the test.

Return Value

The index whose corresponding value in the array passes the test specified by predicate and opts. If the opts bit mask specifies reverse order, then the last item that matches is returned. Otherwise, the index of the first matching object is returned. If no objects in the array pass the test, returns NSNotFound.

Discussion

By default, the enumeration starts with the first object and continues serially through the array to the last object. You can specify NSEnumerationConcurrent and/or NSEnumerationReverse as enumeration options to modify this behavior.

Availability
  • Available in iOS 4.0 and later.
Declared In
NSArray.h

init

Initializes a newly allocated array.

- (instancetype)init
Return Value

An array.

Discussion

After an immutable array has been initialized in this way, it cannot be modified.

This method is a designated initializer.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

initWithArray:

Initializes a newly allocated array by placing in it the objects contained in a given array.

- (instancetype)initWithArray:(NSArray *)anArray
Parameters
anArray

An array.

Return Value

An array initialized to contain the objects in anArray. The returned object might be different than the original receiver.

Discussion

After an immutable array has been initialized in this way, it cannot be modified.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

initWithArray:copyItems:

Initializes a newly allocated array using anArray as the source of data objects for the array.

- (instancetype)initWithArray:(NSArray *)array copyItems:(BOOL)flag
Parameters
array

An array containing the objects with which to initialize the new array.

flag

If YES, each object in array receives a copyWithZone: message to create a copy of the object—objects must conform to the NSCopying protocol. In a managed memory environment, this is instead of the retain message the object would otherwise receive. The object copy is then added to the returned array.

If NO, then in a managed memory environment each object in array simply receives a retain message when it is added to the returned array.

Return Value

An array initialized to contain the objects—or if flag is YES, copies of the objects—in array. The returned object might be different than the original receiver.

Discussion

After an immutable array has been initialized in this way, it cannot be modified.

The copyWithZone: method performs a shallow copy. If you have a collection of arbitrary depth, passing YES for the flag parameter will perform an immutable copy of the first level below the surface. If you pass NO the mutability of the first level is unaffected. In either case, the mutability of all deeper levels is unaffected.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

initWithContentsOfFile:

Initializes a newly allocated array with the contents of the file specified by a given path.

- (id)initWithContentsOfFile:(NSString *)aPath
Parameters
aPath

The path to a file containing a representation of an array produced by the writeToFile:atomically: method.

Return Value

An array initialized to contain the contents of the file specified by aPath or nil if the file can’t be opened or the contents of the file can’t be parsed into an array. The returned object might be different than the original receiver.

Discussion

The array representation in the file identified by aPath must contain only property list objects (NSString, NSData, NSArray, or NSDictionary objects). The objects contained by this array are immutable, even if the array is mutable.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

initWithContentsOfURL:

Initializes a newly allocated array with the contents of the location specified by a given URL.

- (id)initWithContentsOfURL:(NSURL *)aURL
Parameters
aURL

The location of a file containing a string representation of an array produced by the writeToURL:atomically: method.

Return Value

An array initialized to contain the contents specified by aURL. Returns nil if the location can’t be opened or if the contents of the location can’t be parsed into an array. The returned object might be different than the original receiver.

Discussion

The array representation at the location identified by aURL must contain only property list objects (NSString, NSData, NSArray, or NSDictionary objects). The objects contained by this array are immutable, even if the array is mutable.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

initWithObjects:

Initializes a newly allocated array by placing in it the objects in the argument list.

- (instancetype)initWithObjects:(id)firstObj,,...
Parameters
firstObj, ...

A comma-separated list of objects ending with nil.

Return Value

An array initialized to include the objects in the argument list. The returned object might be different than the original receiver.

Discussion

After an immutable array has been initialized in this way, it can’t be modified.

This method is a designated initializer.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

initWithObjects:count:

Initializes a newly allocated array to include a given number of objects from a given C array.

- (instancetype)initWithObjects:(const id [])objects count:(NSUInteger)count
Parameters
objects

A C array of objects.

count

The number of values from the objects C array to include in the new array. This number will be the count of the new array—it must not be negative or greater than the number of elements in objects.

Return Value

A newly allocated array including the first count objects from objects. The returned object might be different than the original receiver.

Discussion

Elements are added to the new array in the same order they appear in objects, up to but not including index count.

After an immutable array has been initialized in this way, it can’t be modified.

This method is a designated initializer.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

isEqualToArray:

Compares the receiving array to another array.

- (BOOL)isEqualToArray:(NSArray *)otherArray
Parameters
otherArray

An array.

Return Value

YES if the contents of otherArray are equal to the contents of the receiving array, otherwise NO.

Discussion

Two arrays have equal contents if they each hold the same number of objects and objects at a given index in each array satisfy the isEqual: test.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

lastObject

Returns the last object in the array.

- (id)lastObject
Return Value

The last object in the array. If the array is empty, returns nil.

Availability
  • Available in iOS 2.0 and later.
See Also
Declared In
NSArray.h

makeObjectsPerformSelector:

Sends to each object in the array the message identified by a given selector, starting with the first object and continuing through the array to the last object.

- (void)makeObjectsPerformSelector:(SEL)aSelector
Parameters
aSelector

A selector that identifies the message to send to the objects in the array. The method must not take any arguments, and must not have the side effect of modifying the receiving array.

Discussion

This method raises an NSInvalidArgumentException if aSelector is NULL.

Availability
  • Available in iOS 2.0 and later.
Related Sample Code
Declared In
NSArray.h

makeObjectsPerformSelector:withObject:

Sends the aSelector message to each object in the array, starting with the first object and continuing through the array to the last object.

- (void)makeObjectsPerformSelector:(SEL)aSelector withObject:(id)anObject
Parameters
aSelector

A selector that identifies the message to send to the objects in the array. The method must take a single argument of type id, and must not have the side effect of modifying the receiving array.

anObject

The object to send as the argument to each invocation of the aSelector method.

Discussion

This method raises an NSInvalidArgumentException if aSelector is NULL.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

objectAtIndex:

Returns the object located at the specified index.

- (id)objectAtIndex:(NSUInteger)index
Parameters
index

An index within the bounds of the array.

Return Value

The object located at index.

Discussion

If index is beyond the end of the array (that is, if index is greater than or equal to the value returned by count), an NSRangeException is raised.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

objectAtIndexedSubscript:

Returns the object at the specified index.

- (id)objectAtIndexedSubscript:(NSUInteger)idx
Parameters
idx

An index within the bounds of the array.

Return Value

The object located at index.

Discussion

If index is beyond the end of the array (that is, if index is greater than or equal to the value returned by count), an NSRangeException is raised.

This method is identical to objectAtIndex:.

Availability
  • Available in iOS 6.0 and later.
Declared In
NSArray.h

objectEnumerator

Returns an enumerator object that lets you access each object in the array.

- (NSEnumerator *)objectEnumerator
Return Value

An enumerator object that lets you access each object in the array, in order, from the element at the lowest index upwards.

Discussion

Returns an enumerator object that lets you access each object in the array, in order, starting with the element at index 0, as in:

NSEnumerator *enumerator = [myArray objectEnumerator];
id anObject;
 
while (anObject = [enumerator nextObject]) {
    /* code to act on each element as it is returned */
}
Special Considerations

When you use this method with mutable subclasses of NSArray, you must not modify the array during enumeration.

It is more efficient to use the fast enumeration protocol (see NSFastEnumeration). Fast enumeration is available on OS X v10.5 and later and iOS 2.0 and later.

Availability
  • Available in iOS 2.0 and later.
Related Sample Code
Declared In
NSArray.h

objectsAtIndexes:

Returns an array containing the objects in the array at the indexes specified by a given index set.

- (NSArray *)objectsAtIndexes:(NSIndexSet *)indexes
Return Value

An array containing the objects in the array at the indexes specified by indexes.

Discussion

The returned objects are in the ascending order of their indexes in indexes, so that object in returned array with higher index in indexes will follow the object with smaller index in indexes.

Raises an NSRangeException if any location in indexes exceeds the bounds of the array, indexes is nil.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

pathsMatchingExtensions:

Returns an array containing all the pathname elements in the receiving array that have filename extensions from a given array.

- (NSArray *)pathsMatchingExtensions:(NSArray *)filterTypes
Parameters
filterTypes

An array of NSString objects containing filename extensions. The extensions should not include the dot (“.”) character.

Return Value

An array containing all the pathname elements in the receiving array that have filename extensions from the filterTypes array.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSPathUtilities.h

removeObserver:forKeyPath:

Raises an exception.

- (void)removeObserver:(NSObject *)observer forKeyPath:(NSString *)keyPath
Parameters
observer

The object to remove as an observer.

keyPath

A key-path, relative to the array, for which observer is registered to receive KVO change notifications. This value must not be nil.

Special Considerations

NSArray objects are not observable, so this method raises an exception when invoked on an NSArray object. Instead of observing an array, observe the to-many relationship for which the array is the collection of related objects.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSKeyValueObserving.h

removeObserver:forKeyPath:context:

Raises an exception.

- (void)removeObserver:(NSObject *)observer forKeyPath:(NSString *)keyPath context:(void *)context
Parameters
observer

The object to remove as an observer.

keyPath

A key-path, relative to the set, for which observer is registered to receive KVO change notifications. This value must not be nil.

context

The context passed to the notifications.

Special Considerations

NSArray objects are not observable, so this method raises an exception when invoked on an NSArray object. Instead of observing a array, observe the ordered to-many relationship for which the array is the collection of related objects.

Availability
  • Available in iOS 5.0 and later.
Declared In
NSKeyValueObserving.h

removeObserver:fromObjectsAtIndexes:forKeyPath:

Removes anObserver from all key value observer notifications associated with the specified keyPath relative to the array’s objects at indexes.

- (void)removeObserver:(NSObject *)anObserver fromObjectsAtIndexes:(NSIndexSet *)indexes forKeyPath:(NSString *)keyPath
Parameters
anObserver

The observer.

indexes

The index set.

keyPath

The key path, relative to the array, to be observed.

Discussion

This is not merely a convenience method; invoking this method is potentially much faster than repeatedly invoking removeObserver:forKeyPath:.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSKeyValueObserving.h

removeObserver:fromObjectsAtIndexes:forKeyPath:context:

Raises an exception.

- (void)removeObserver:(NSObject *)observer fromObjectsAtIndexes:(NSIndexSet *)indexes forKeyPath:(NSString *)keyPath context:(void *)context
Parameters
observer

The object to remove as an observer.

keyPath

A key-path, relative to the array, for which observer is registered to receive KVO change notifications. This value must not be nil.

context

The context passed to the notifications.

Special Considerations

NSArray objects are not observable, so this method raises an exception when invoked on an NSArray object. Instead of observing an array, observe the to-many relationship for which the array is the collection of related objects.

Availability
  • Available in iOS 5.0 and later.
Declared In
NSKeyValueObserving.h

reverseObjectEnumerator

Returns an enumerator object that lets you access each object in the array, in reverse order.

- (NSEnumerator *)reverseObjectEnumerator
Return Value

An enumerator object that lets you access each object in the array, in order, from the element at the highest index down to the element at index 0.

Special Considerations

When you use this method with mutable subclasses of NSArray, you must not modify the array during enumeration.

It is more efficient to use the fast enumeration protocol (see NSFastEnumeration). Fast enumeration is available on OS X v10.5 and later and iOS 2.0 and later.

Availability
  • Available in iOS 2.0 and later.
See Also
Declared In
NSArray.h

setValue:forKey:

Invokes setValue:forKey: on each of the array's items using the specified value and key.

- (void)setValue:(id)value forKey:(NSString *)key
Parameters
value

The object value.

key

The key to store the value.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSKeyValueCoding.h

sortedArrayHint

Analyzes the array and returns a “hint” that speeds the sorting of the array when the hint is supplied to sortedArrayUsingFunction:context:hint:.

- (NSData *)sortedArrayHint
Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

sortedArrayUsingComparator:

Returns an array that lists the receiving array’s elements in ascending order, as determined by the comparison method specified by a given NSComparator Block.

- (NSArray *)sortedArrayUsingComparator:(NSComparator)cmptr
Parameters
cmptr

A comparator block.

Return Value

An array that lists the receiving array’s elements in ascending order, as determined by the comparison method specified cmptr.

Availability
  • Available in iOS 4.0 and later.
Declared In
NSArray.h

sortedArrayUsingDescriptors:

Returns a copy of the receiving array sorted as specified by a given array of sort descriptors.

- (NSArray *)sortedArrayUsingDescriptors:(NSArray *)sortDescriptors
Parameters
sortDescriptors

An array of NSSortDescriptor objects.

Return Value

A copy of the receiving array sorted as specified by sortDescriptors.

Discussion

The first descriptor specifies the primary key path to be used in sorting the receiving array’s contents. Any subsequent descriptors are used to further refine sorting of objects with duplicate values. See NSSortDescriptor for additional information.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSSortDescriptor.h

sortedArrayUsingFunction:context:

Returns a new array that lists the receiving array’s elements in ascending order as defined by the comparison function comparator.

- (NSArray *)sortedArrayUsingFunction:(NSInteger (*)(id, id, void *))comparator context:(void *)context
Discussion

The new array contains references to the receiving array’s elements, not copies of them.

The comparison function is used to compare two elements at a time and should return NSOrderedAscending if the first element is smaller than the second, NSOrderedDescending if the first element is larger than the second, and NSOrderedSame if the elements are equal. Each time the comparison function is called, it’s passed context as its third argument. This allows the comparison to be based on some outside parameter, such as whether character sorting is case-sensitive or case-insensitive.

Given anArray (an array of NSNumber objects) and a comparison function of this type:

NSInteger intSort(id num1, id num2, void *context)
{
    int v1 = [num1 intValue];
    int v2 = [num2 intValue];
    if (v1 < v2)
        return NSOrderedAscending;
    else if (v1 > v2)
        return NSOrderedDescending;
    else
        return NSOrderedSame;
}

A sorted version of anArray is created in this way:

NSArray *sortedArray; sortedArray = [anArray sortedArrayUsingFunction:intSort context:NULL];
Availability
  • Available in iOS 2.0 and later.
Related Sample Code
Declared In
NSArray.h

sortedArrayUsingFunction:context:hint:

Returns a new array that lists the receiving array’s elements in ascending order as defined by the comparison function comparator.

- (NSArray *)sortedArrayUsingFunction:(NSInteger (*)(id, id, void *))comparator context:(void *)context hint:(NSData *)hint
Discussion

The new array contains references to the receiving array’s elements, not copies of them.

This method is similar to sortedArrayUsingFunction:context:, except that it uses the supplied hint to speed the sorting process. When you know the array is nearly sorted, this method is faster than sortedArrayUsingFunction:context:. If you sorted a large array (N entries) once, and you don’t change it much (P additions and deletions, where P is much smaller than N), then you can reuse the work you did in the original sort by conceptually doing a merge sort between the N “old” items and the P “new” items.

To obtain an appropriate hint, use sortedArrayHint. You should obtain this hint when the original array has been sorted, and keep hold of it until you need it, after the array has been modified. The hint is computed by sortedArrayHint in O(N) (where N is the number of items). This assumes that items in the array implement a -hash method. Given a suitable hint, and assuming that the hash function is a “good” hash function, -sortedArrayUsingFunction:context:hint: sorts the array in O(P*LOG(P)+N) where P is the number of adds or deletes. This is an improvement over the un-hinted sort, O(N*LOG(N)), when P is small.

The hint is simply an array of size N containing the N hashes. To re-sort you need internally to create a map table mapping a hash to the index. Using this map table on the new array, you can get a first guess for the indices, and then sort that. For example, a sorted array {A, B, D, E, F} with corresponding hash values {25, 96, 78, 32, 17}, may be subject to small changes that result in contents {E, A, C, B, F}. The mapping table maps the hashes {25, 96, 78, 32, 17} to the indices {#0, #1, #2, #3, #4}. If the hashes for {E, A, C, B, F} are {32, 25, 99, 96, 17}, then by using the mapping table you can get a first order sort {#3, #0, ?, #1, #4}, so therefore create an initial semi-sorted array {A, B, E, F}, and then perform a cheap merge sort with {C} that yields {A, B, C, E, F}.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

sortedArrayUsingSelector:

Returns an array that lists the receiving array’s elements in ascending order, as determined by the comparison method specified by a given selector.

- (NSArray *)sortedArrayUsingSelector:(SEL)comparator
Parameters
comparator

A selector that identifies the method to use to compare two elements at a time. The method should return NSOrderedAscending if the receiving array is smaller than the argument, NSOrderedDescending if the receiving array is larger than the argument, and NSOrderedSame if they are equal.

Return Value

An array that lists the receiving array’s elements in ascending order, as determined by the comparison method specified by the selector comparator.

Discussion

The new array contains references to the receiving array’s elements, not copies of them.

The comparator message is sent to each object in the array and has as its single argument another object in the array.

For example, an array of NSString objects can be sorted by using the caseInsensitiveCompare: method declared in the NSString class. Assuming anArray exists, a sorted version of the array can be created in this way:

     NSArray *sortedArray =
         [anArray sortedArrayUsingSelector:@selector(caseInsensitiveCompare:)];
Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

sortedArrayWithOptions:usingComparator:

Returns an array that lists the receiving array’s elements in ascending order, as determined by the comparison method specified by a given NSComparator Block.

- (NSArray *)sortedArrayWithOptions:(NSSortOptions)opts usingComparator:(NSComparator)cmptr
Parameters
opts

A bit mask that specifies the options for the sort (whether it should be performed concurrently and whether it should be performed stably).

cmptr

A comparator block.

Return Value

An array that lists the receiving array’s elements in ascending order, as determined by the comparison method specified cmptr.

Availability
  • Available in iOS 4.0 and later.
Declared In
NSArray.h

subarrayWithRange:

Returns a new array containing the receiving array’s elements that fall within the limits specified by a given range.

- (NSArray *)subarrayWithRange:(NSRange)range
Parameters
range

A range within the receiving array’s range of elements.

Return Value

A new array containing the receiving array’s elements that fall within the limits specified by range.

Discussion

If range isn’t within the receiving array’s range of elements, an NSRangeException is raised.

For example, the following code example creates an array containing the elements found in the first half of wholeArray (assuming wholeArray exists).

NSArray *halfArray;
NSRange theRange;
 
theRange.location = 0;
theRange.length = [wholeArray count] / 2;
 
halfArray = [wholeArray subarrayWithRange:theRange];
Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

valueForKey:

Returns an array containing the results of invoking valueForKey: using key on each of the array's objects.

- (id)valueForKey:(NSString *)key
Parameters
key

The key to retrieve.

Return Value

The value of the retrieved key.

Discussion

The returned array contains NSNull elements for each object that returns nil.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSKeyValueCoding.h

writeToFile:atomically:

Writes the contents of the array to a file at a given path.

- (BOOL)writeToFile:(NSString *)path atomically:(BOOL)flag
Parameters
path

The path at which to write the contents of the array.

If path contains a tilde (~) character, you must expand it with stringByExpandingTildeInPath before invoking this method.

flag

If YES, the array is written to an auxiliary file, and then the auxiliary file is renamed to path. If NO, the array is written directly to path. The YES option guarantees that path, if it exists at all, won’t be corrupted even if the system should crash during writing.

Return Value

YES if the file is written successfully, otherwise NO.

Discussion

If the array’s contents are all property list objects (NSString, NSData, NSArray, or NSDictionary objects), the file written by this method can be used to initialize a new array with the class method arrayWithContentsOfFile: or the instance method initWithContentsOfFile:. This method recursively validates that all the contained objects are property list objects before writing out the file, and returns NO if all the objects are not property list objects, since the resultant file would not be a valid property list.

Availability
  • Available in iOS 2.0 and later.
Related Sample Code
Declared In
NSArray.h

writeToURL:atomically:

Writes the contents of the array to the location specified by a given URL.

- (BOOL)writeToURL:(NSURL *)aURL atomically:(BOOL)flag
Parameters
aURL

The location at which to write the array.

flag

If YES, the array is written to an auxiliary location, and then the auxiliary location is renamed to aURL. If NO, the array is written directly to aURL. The YES option guarantees that aURL, if it exists at all, won’t be corrupted even if the system should crash during writing.

Return Value

YES if the location is written successfully, otherwise NO.

Discussion

If the array’s contents are all property list objects (NSString, NSData, NSArray, or NSDictionary objects), the location written by this method can be used to initialize a new array with the class method arrayWithContentsOfURL: or the instance method initWithContentsOfURL:.

Availability
  • Available in iOS 2.0 and later.
Declared In
NSArray.h

Constants

NSBinarySearchingOptions

Options for searches and insertions using indexOfObject:inSortedRange:options:usingComparator:.

enum {
   NSBinarySearchingFirstEqual = (1 << 8),
   NSBinarySearchingLastEqual = (1 << 9),
   NSBinarySearchingInsertionIndex = (1 << 10),
};
typedef NSUInteger NSBinarySearchingOptions;
Constants
NSBinarySearchingFirstEqual

Specifies that the search should return the first object in the range that is equal to the given object.

Available in iOS 4.0 and later.

Declared in NSArray.h.

NSBinarySearchingLastEqual

Specifies that the search should return the last object in the range that is equal to the given object.

Available in iOS 4.0 and later.

Declared in NSArray.h.

NSBinarySearchingInsertionIndex

Returns the index at which you should insert the object in order to maintain a sorted array.

Available in iOS 4.0 and later.

Declared in NSArray.h.