Objective-C Numbers

In Objective-C programming language, in order to save the basic data types like int, float, bool in object form,
Objective-C provides a range of methods to work with NSNumber and important ones are listed in following table.

S.N.	Method and Description
1	+ (NSNumber *)numberWithBool:(BOOL)value Creates and returns an NSNumber object containing a given value, treating it as a BOOL.
2	+ (NSNumber *)numberWithChar:(char)value Creates and returns an NSNumber object containing a given value, treating it as a signed char.
3	+ (NSNumber *)numberWithDouble:(double)value Creates and returns an NSNumber object containing a given value, treating it as a double.
4	+ (NSNumber *)numberWithFloat:(float)value Creates and returns an NSNumber object containing a given value, treating it as a float.
5	+ (NSNumber *)numberWithInt:(int)value Creates and returns an NSNumber object containing a given value, treating it as a signed int.
6	+ (NSNumber *)numberWithInteger:(NSInteger)value Creates and returns an NSNumber object containing a given value, treating it as an NSInteger.
7	- (BOOL)boolValue Returns the receiver's value as a BOOL.
8	- (char)charValue Returns the receiver's value as a char.
9	- (double)doubleValue Returns the receiver's value as a double.
10	- (float)floatValue Returns the receiver's value as a float.
11	- (NSInteger)integerValue Returns the receiver's value as an NSInteger.
12	- (int)intValue Returns the receiver's value as an int.
13	- (NSString *)stringValue Returns the receiver's value as a human-readable string.

Here is a simple example for using NSNumber which multiplies two numbers and returns the product.

#import <Foundation/Foundation.h>

@interface SampleClass:NSObject

- (NSNumber *)multiplyA:(NSNumber *)a withB:(NSNumber *)b;

@end

@implementation SampleClass

- (NSNumber *)multiplyA:(NSNumber *)a withB:(NSNumber *)b
{
   float number1 = [a floatValue];
   float number2 = [b floatValue];
   float product = number1 * number2;
   NSNumber *result = [NSNumber numberWithFloat:product];
   return result;
}

@end

int main()
{
   NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

   SampleClass *sampleClass = [[SampleClass alloc]init];
   NSNumber *a = [NSNumber numberWithFloat:10.5];
   NSNumber *b = [NSNumber numberWithFloat:10.0];   
   NSNumber *result = [sampleClass multiplyA:a withB:b];
   NSString *resultString = [result stringValue];
   NSLog(@"The product is %@",resultString);

   [pool drain];
   return 0;
}

Now when we compile and run the program, we will get the following result.

2013-09-14 18:53:40.575 demo[16787] The product is 105