NSNumber

NSNumber可以包装常规的C类型成为一个Objective-C对象，可以存储任何的数字类型，以及BOOL和char。

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[])
{

    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    NSMutableArray *array = [NSMutableArray arrayWithCapacity:3];
    [array addObject:[NSNumber numberWithInt:1]];
    [array addObject:[NSNumber numberWithFloat:1.0]];
    [array addObject:[NSNumber numberWithBool:TRUE]];
    [array addObject:[NSNumber numberWithBool:FALSE]];
    [array addObject:[NSNumber numberWithChar:'$']];
    
    NSLog(@"%@", array);

    [pool drain];
    return 0;
}

返回结果：

2011-05-06 10:07:26.802 demo07[3689:903] (
    1,
    1,
    1,
    0,
    36
)