黑马培训之IOS学习--Foundation--dictionary字典的使用

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////  main.m//  05--dictionary字典的使用////  Created by LeeWong on 14-10-25.//  Copyright (c) 2014年 LeeWong. All rights reserved.//#import <Foundation/Foundation.h>int main() {    //字典的便利    //1.for循环    NSDictionary *dict1 = @{@"name":@"jack",@"address":@"北京",@"qq":@"67788989"};        //获取字典中所有的key值    NSArray *keys = [dict1 allKeys];    for(int i = 0; i< dict1.count; i++)    {        NSString *key = keys[i];        NSString *object = dict1[key];        NSLog(@"%@-----%@",key,object);    }        //利用block    [dict1 enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {        NSLog(@"%@---%@",key,obj);        /*        可以根据需求 让程序运行几次后停止         */    }];        return 0;}void test1(){    //可变字典        //创建    //方法基本同不可变字典相同    NSMutableDictionary *dict1 = [NSMutableDictionary dictionary];        //这种定义方法是错误的 @{}只能用于创建和初始化一个不可变字典    //NSMutableDictionary *dict2 = @{@"name":@"lee",@"address":@"北京",@"qq":@"485729845"};        //添加键值对    [dict1 setObject:@"jack" forKey:@"name"];    [dict1 setObject:@"北京" forKey:@"address"];    [dict1 setObject:@"72589472" forKey:@"qq"];        NSLog(@"%@",dict1);        //删除键值对    [dict1 removeObjectForKey:@"name"];    NSLog(@"%@",dict1);}void test(){    //不可变字典的使用    //NSDictionary 其实际存放的时键值对        //创建    NSDictionary *dict1 = [NSDictionary dictionary];//永远为空        NSDictionary *dict2 = [NSDictionary dictionaryWithObject:@"jack" forKey:@"name"];        NSDictionary *dict3 = [NSDictionary dictionaryWithObjectsAndKeys:                           @"jack",@"name",                           @"北京",@"address",                           @"6789879",@"qq",                           nil];            NSArray *key = @[@"name",@"address",@"qq"];    NSArray *object = @[@"lee",@"北京",@"289475984"];        NSDictionary *dict4 = [NSDictionary dictionaryWithObjects:object forKeys:key];        NSLog(@"%@",dict4);        //最常用的创建方法    NSDictionary *dict5 = @{@"name":@"jack",@"address":@"北京",@"qq":@"67788989"};            //根据键值找到对象值    NSLog(@"%@",[dict4 objectForKey:@"address"]);    NSString *name = dict5[@"name"];    NSLog(@"%@",name);        //字典中键值对的个数    NSLog(@"%d",dict3.count);}
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