NSDictionary Class Reference

Tasks

Creating a Dictionary

• + dictionary
• + dictionaryWithContentsOfFile:
• + dictionaryWithContentsOfURL:
• + dictionaryWithDictionary:
• + dictionaryWithObject:forKey:
• + dictionaryWithObjects:forKeys:
• + dictionaryWithObjects:forKeys:count:
• + dictionaryWithObjectsAndKeys:

Initializing an NSDictionary Instance

• – initWithContentsOfFile:
• – initWithContentsOfURL:
• – initWithDictionary:
• – initWithDictionary:copyItems:
• – initWithObjects:forKeys:
• – initWithObjects:forKeys:count:
• – initWithObjectsAndKeys:

Creating Key Sets for Shared-Key Optimized Dictionaries

• + sharedKeySetForKeys:

Counting Entries

• – count

Comparing Dictionaries

• – isEqualToDictionary:

Accessing Keys and Values

• – allKeys
• – allKeysForObject:
• – allValues
• – getObjects:andKeys:
• – objectForKey:
• – objectForKeyedSubscript:
• – objectsForKeys:notFoundMarker:
• – valueForKey:

Enumerating Dictionaries

• – keyEnumerator
• – objectEnumerator
• – enumerateKeysAndObjectsUsingBlock:
• – enumerateKeysAndObjectsWithOptions:usingBlock:

Sorting Dictionaries

• – keysSortedByValueUsingSelector:
• – keysSortedByValueUsingComparator:
• – keysSortedByValueWithOptions:usingComparator:

Filtering Dictionaries

• – keysOfEntriesPassingTest:
• – keysOfEntriesWithOptions:passingTest:

Storing Dictionaries

• – writeToFile:atomically:
• – writeToURL:atomically:

Accessing File Attributes

• – fileCreationDate
• – fileExtensionHidden
• – fileGroupOwnerAccountID
• – fileGroupOwnerAccountName
• – fileHFSCreatorCode
• – fileHFSTypeCode
• – fileIsAppendOnly
• – fileIsImmutable
• – fileModificationDate
• – fileOwnerAccountID
• – fileOwnerAccountName
• – filePosixPermissions
• – fileSize
• – fileSystemFileNumber
• – fileSystemNumber
• – fileType

Creating a Description

• – description
• – descriptionInStringsFileFormat
• – descriptionWithLocale:
• – descriptionWithLocale:indent:

static const NSInteger N_ENTRIES = 26;

NSDictionary *asciiDict;

NSString *keyArray[N_ENTRIES];

NSNumber *valueArray[N_ENTRIES];

NSInteger i;

for (i = 0; i < N_ENTRIES; i++) {

    char charValue = 'a' + i;

    keyArray[i] = [NSString stringWithFormat:@"%c", charValue];

    valueArray[i] = [NSNumber numberWithChar:charValue];

}

asciiDict = [NSDictionary dictionaryWithObjects:(id *)valueArray

                          forKeys:(id *)keyArray count:N_ENTRIES];

NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:

    @"value1", @"key1", @"value2", @"key2", nil];

NSDictionary *dict = [[NSDictionary alloc] initWithObjectsAndKeys:

    @"value1", @"key1", @"value2", @"key2", nil];

NSEnumerator *enumerator = [myDictionary keyEnumerator];

id key;

while ((key = [enumerator nextObject])) {

    /* code that uses the returned key */

}

NSEnumerator *enumerator = [myDictionary objectEnumerator];

id value;

while ((value = [enumerator nextObject])) {

    /* code that acts on the dictionary’s values */

}