字典NSDictionary

//
//  main.m
//  字典dictionary
//
//  Created by MAC on 15/12/20.
//  Copyright © 2015年 MAC. All rights reserved.
//

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        //创建字典
        NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:@"one",@"1",@"two",@"2",@"three",@"3", nil];
        NSDictionary *dict2 = [NSDictionary dictionaryWithObjectsAndKeys:@"a",@"1",@"a",@"2",@"a",@"3", nil];
      //  dict2 = [NSDictionary dictionaryWithDictionary:dict];
        //查找Key为2的Value
        NSLog(@"%@",[dict objectForKey:@"2"]);
        NSLog(@"%@",dict2);
        //用两个数组创建字典
        NSArray *key = @[@"5",@"6",@"7"];//如果Key重复 只保留第一个VALUE
        NSArray *value = @[@"Android",@"IOS",@"cocos2dx"];
        NSDictionary *dict3 = [NSDictionary dictionaryWithObjects:value forKeys:key];
        NSLog(@"%@",dict3);
        for (NSString *a in dict) {
            NSLog(@"%@",[dict objectForKey:a]);
        }
        //key的枚举 也可以object的枚举
        NSEnumerator *enu = [dict keyEnumerator];
        NSString *a;
        while ((a=[enu nextObject])!=nil) {
            NSString *value = [dict objectForKey:a];
            NSLog(@"%@:%@",a,value);
        }
        key = dict.allKeys;
        value = dict.allValues;
        for (NSObject *a in key) {
            NSLog(@"%@",a);
        }
        for (NSObject *a in value) {
            NSLog(@"%@",a);
        }
        //获得所有的key and value
        __block int count=0;
        [dict enumerateKeysAndObjectsUsingBlock:^(id  _Nonnull key, id  _Nonnull obj, BOOL * _Nonnull stop) {
            if(++count>1){
                *stop = YES;//执行两次 就获取前两对
            }
            NSLog(@"000%@,%@",key,obj);
        }];
        
        //字典写入文件
      BOOL b= [dict writeToFile:@"/Users/mac/desktop/test.txt" atomically:YES];
        NSLog(@"%d",b);
        //从文件读取赋值给字典
        dict3 = [NSDictionary dictionaryWithContentsOfFile:@"/Users/mac/desktop/test.txt"];
        NSLog(@"ww%@",dict3);
    }
    return 0;
}