OC-1-8

//
//  main.m
//  nsDictionary
//
//  Created by syrcfwzx on 16/1/8.
//  Copyright (c) 2016年 syrcfwzx. All rights reserved.
//

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        
        //注意key 通常是字符串对象
        NSMutableDictionary* dic = [[NSMutableDictionary alloc]initWithObjectsAndKeys:@"jay",@"name",@"22",@"age",@"f",@"gender", nil];
         NSLog(@"%@",dic);
        NSDictionary* dic1 = [NSDictionary dictionaryWithObject:@"166" forKey:@"height"];
        [dic addEntriesFromDictionary:dic1];
        NSLog(@"%@",dic);
        [dic setObject:@"66" forKey:@"weight"];
         NSLog(@"%@",dic);
        //遍历
        //1.先找到所有的key 2计算key的个数
        NSArray* array = [dic allKeys];
        NSInteger count = [dic count];
        for(int i = 0;i<count;i++)
        {
            id key = [array objectAtIndex:i];
            NSLog(@"%@",[dic objectForKey:key]);
        }
        //for in语法
        for(id key in array)
        {
            id obj=[dic objectForKey:key];
            NSLog(@"%@",obj);
        }
        //block遍历
        [dic enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
        
            NSLog(@"key=%@ obj=%@",key,obj);
        }];
        //3通过枚举对象进行枚举
        //将字典里的key转成枚举对象 用于遍历
        NSEnumerator* enumerator = [dic keyEnumerator];
        id key;
        while (key=[enumerator nextObject]) {
            id obj3 = [dic objectForKey:key];
            NSLog(@"%@",obj3);
        }
        
        
    }
    return 0;
}
原文地址:https://www.cnblogs.com/hezhuangzhuang/p/5112267.html