NSIntegerdecodeIntegerForKeyNSString

NSIntegerdecodeIntegerForKeyNSString refers to decoding an NSInteger value from an archived data store using a Keyed Archiver/Unarchiver pattern, where the key is an NSString. NSInteger is a signed integer type defined by the Objective-C runtime, sized to match the platform’s word length (32-bit on 32-bit systems, 64-bit on 64-bit systems). In Apple’s Foundation framework, values are encoded with encodeInteger:forKey: and later decoded with decodeIntegerForKey:. The key parameter is an NSString that identifies the stored value within the archive, and it must match the key used during encoding.

Typically, decoding occurs within a decoding context such as an NSKeyedUnarchiver or a class that inherits from NSCoder. A common usage is NSInteger value = [decoder decodeIntegerForKey:@"someKey"]; where decoder is an instance of NSCoder or NSKeyedUnarchiver. In Swift, the equivalent call uses decodeInteger(forKey:) and returns a Swift Int, with the key provided as a String.

The method is specialized for NSInteger and differs from related primitive decoders like decodeIntForKey: or decodeIntegerForKey: when exact sizing matters across architectures. Developers should use the appropriate method corresponding to the encoded type. The corresponding encoding method is encodeInteger:forKey:. Care should be taken to ensure the same key is used for both encoding and decoding, and that the decoding context is properly initialized before calling the method.

See also: NSCoder, NSKeyedUnarchiver, encodeInteger:forKey:, decodeObjectForKey:, and the Swift bridging where NSInteger maps to Int. This pattern is part of keyed archiving and unarchiving used to persist simple scalar values alongside objects.