foundation-NSNumber

////  main.m//  foundation-NSNumber////  Created by apple on 15/7/3.//  Copyright (c) 2015年 itcast. All rights reserved.//#import <Foundation/Foundation.h>void number(){    //将int类型包装成一个nsnumber    NSNumber *number = [NSNumber numberWithInt:10];    NSMutableArray *arr = [NSMutableArray array];    //添加数值到数组中    [arr addObject:number];    //取出来的还是nsnumber,不会自动拆箱    NSNumber *num = [arr lastObject];    //将nsnumber转换成int    int i = [num intValue];    NSLog(@"%i",i);}int main(int argc, const char * argv[]) {    @autoreleasepool {        number();    }    return 0;}