Foundation Data Types Reference

Overview

This document describes the data types and constants found in the Foundation framework.

Data Types

NSComparator

Defines the signature for a block object used for comparison operations.

typedef NSComparisonResult (^NSComparator)(id obj1, id obj2);

NSArray *sortedArray = [array sortedArrayUsingComparator: ^(id obj1, id obj2) {

    if ([obj1 integerValue] > [obj2 integerValue]) {

        return (NSComparisonResult)NSOrderedDescending;

    }

    if ([obj1 integerValue] < [obj2 integerValue]) {

        return (NSComparisonResult)NSOrderedAscending;

    }

    return (NSComparisonResult)NSOrderedSame;

}];

NSDecimal

Used to describe a decimal number.

typedef struct {
      signed int _exponent:8;
      unsigned int _length:4;
      unsigned int _isNegative:1;
      unsigned int _isCompact:1;
      unsigned int _reserved:18;
      unsigned short _mantissa[NSDecimalMaxSize];
} NSDecimal;

NSHashTableOptions

Specifies a bitfield used to configure the behavior of elements in an instance of NSHashTable.

typedef NSUInteger NSHashTableOptions

NSInteger

Used to describe an integer.

typedef long NSInteger;

NSMapTableOptions

Specifies a bitfield used to configure the behavior of elements in an instance of NSMapTable.

typedef NSUInteger NSMapTableOptions

NSRange

A structure used to describe a portion of a series—such as characters in a string or objects in an NSArray object.

typedef struct _NSRange {
      NSUInteger location;
      NSUInteger length;
} NSRange;

Fields

location

The start index (0 is the first, as in C arrays).

length

The number of items in the range (can be 0).

NSRangePointer

Type indicating a parameter is a pointer to an NSRange structure.

typedef NSRange *NSRangePointer;

NSSocketNativeHandle

Type for the platform-specific native socket handle.

typedef int NSSocketNativeHandle;

NSStringEncoding

Type representing string-encoding values.

typedef NSUInteger NSStringEncoding;

NSSwappedDouble

Opaque structure containing endian-independent double value.

typedef struct {
      unsigned long long v;
} NSSwappedDouble;

NSSwappedFloat

Opaque type containing an endian-independent float value.

typedef struct {
      unsigned int v;
} NSSwappedFloat;

NSTimeInterval

Used to specify a time interval, in seconds.

typedef double NSTimeInterval;

NSUncaughtExceptionHandler

Used for the function handling exceptions outside of an exception-handling domain.

typedef volatile void NSUncaughtExceptionHandler(NSException *exception);

NSUInteger

Used to describe an unsigned integer.

typedef unsigned long NSUInteger;

NSZone

Used to identify and manage memory zones.

typedef struct _NSZone NSZone;