Global Variable


A value indicating that a requested item couldn’t be found or doesn’t exist.


const NSInteger NSNotFound;


NSNotFound is typically used by various methods and functions that search for items in serial data and return indices, such as characters in a string object or id objects in an NSArray object.

Special Considerations

Prior to OS X v10.5, NSNotFound was defined as 0x7fffffff. For 32-bit systems, this was effectively the same as NSIntegerMax. To support 64-bit environments, NSNotFound is now formally defined as NSIntegerMax. This means, however, that the value is different in 32-bit and 64-bit environments. You should therefore not save the value directly in files or archives. Moreover, sending the value between 32-bit and 64-bit processes via Distributed Objects will not get you NSNotFound on the other side. This applies to any Cocoa methods invoked over Distributed Objects and which might return NSNotFound, such as the indexOfObject: method of NSArray (if sent to a proxy for an array).

See Also

Pattern Matching


A string parser that scans for substrings or characters in a character set, and for numeric values from decimal, hexadecimal, and floating-point representations.


An immutable representation of a compiled regular expression that you apply to Unicode strings.


A specialized regular expression object that matches natural language text for predefined data patterns.


An occurrence of textual content found during the analysis of a block of text, such as when matching a regular expression.