OC3_字典

//
//  main.m
//  OC3_字典
//
//  Created by zhangxueming on 15/6/12.
//  Copyright (c) 2015年 zhangxueming. All rights reserved.
//

#import <Foundation/Foundation.h>
//NSDictionary
//创建一个不可变字典对象
//NSMutableDictionary
//创建一个可变字典对象

//字典中对象都是键值对
//key:value
//字典中的键值对没有顺序
//字典中的key是唯一的, 但是value不一定是唯一的

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        //用value 及 key 构造字典对象
        NSDictionary *dict = [[NSDictionary alloc] initWithObjectsAndKeys:@"1",@"one",@"2",@"two",@"3",@"three",@"4",@"four",@"4",@"five",@"4",@"six", nil];
        NSLog(@"dict = %@", dict);
        //创建常量字典对象
        NSDictionary *dict2 = @{@"one":@"1",@"two":@"2"};
        NSLog(@"dict2 = %@", dict2);
        
        //用传入的字典对象创建字典对象
        NSDictionary *dict3 = [[NSDictionary alloc] initWithDictionary:dict];
        NSLog(@"dict3 = %@", dict3);
        
        //用传入的value数组及key数组创建字典对象
        NSDictionary *dict4 = [[NSDictionary alloc] initWithObjects:@[@"3",@"4",@"5",@"6"] forKeys:@[@"three",@"four",@"five",@"six"]];
        NSLog(@"dict4 = %@", dict4);
        
        //创建一个空的字典对象
        NSDictionary *dict5 = [[NSDictionary alloc] init];
        NSLog(@"dict5 = %@", dict5);
        
        //类方法创建字典对象
        //跟initWithObjectsAndKeys:方法对应
        NSDictionary *dict6 = [NSDictionary dictionaryWithObjectsAndKeys:@"1",@"one",@"2",@"two",@"3",@"three", nil];
        NSLog(@"dict6 = %@", dict6);
        //跟initWithObjects:forKeys:相对应
        NSDictionary *dict7 = [NSDictionary dictionaryWithObjects:@[@"3",@"4",@"5",@"6"] forKeys:@[@"three",@"four",@"five",@"six"]];
        NSLog(@"dict7 = %@", dict7);
        
        //跟initWithDictionary:相对应
        NSDictionary *dict8 = [NSDictionary dictionaryWithDictionary:dict7];
        NSLog(@"dict8 = %@", dict8);
        
        //计算字典中键值对的个数
        NSUInteger len = [dict count];
        NSLog(@"len = %li", len);
        
        //获取key对应的值
        id value = [dict objectForKey:@"two"];
        NSLog(@"value = %@", value);
        
        //获取所有的key
        NSArray *keys = [dict allKeys];
        NSLog(@"keys = %@", keys);
        
        //获取值对应所有的key
        NSArray *keys2 = [dict allKeysForObject:@"4"];
        NSLog(@"keys2 = %@", keys2);
        
        //获取所有的值
        NSArray *values = [dict allValues];
        NSLog(@"values = %@", values);
        
        //判断两个字典是否相等
        BOOL ret = [dict isEqualToDictionary:dict2];
        NSLog(@"ret = %i", ret);
        
        //遍历字典 -- 实际上是遍历字典的key
        
        //枚举器法
        NSEnumerator *keysArray = [dict keyEnumerator];
        for (id item in keysArray) {
            NSLog(@"%@:%@",item,[dict objectForKey:item]);
        }
        //快速枚举法
        for (id key in dict) {
            NSLog(@"%@:%@", key, [dict objectForKey:key]);
        }
        //只遍历字典中的值
        NSEnumerator *valuesArray = [dict objectEnumerator];
        for (id item in valuesArray) {
            NSLog(@"vlaue = %@", item);
        }
        
        //可变字典操作
        //构造指定容量大小的字典对象
        //+ (instancetype)dictionaryWithCapacity:(NSUInteger)numItems;
        NSMutableDictionary *mulDict = [[NSMutableDictionary alloc] initWithCapacity:20];
        NSLog(@"mulDict = %@",mulDict);
        
        //删除指定的key对应的键值对
        NSMutableDictionary *mulDict2 = [NSMutableDictionary dictionaryWithDictionary:@{@"one":@"1",@"two":@"2",@"three":@"3",@"four":@"4"}];
        [mulDict2 removeObjectForKey:@"two"];
        NSLog(@"mulDict2 = %@", mulDict2);
        //添加(或者修改)键值对
        [mulDict2 setObject:@"5" forKey:@"three"];
        NSLog(@"mulDict2 = %@", mulDict2);
        
        //将传入字典中的键值对添加到字典中  相同的修改，不同的就添加
        [mulDict2 addEntriesFromDictionary:dict3];
        NSLog(@"mulDict2 = %@", mulDict2);
        
        //删除所有的键值对
        [mulDict2 removeAllObjects];
        NSLog(@"mulDict2 = %@", mulDict2);
        
        //删除key数组对应所有键值对
        NSMutableDictionary *mulDict3 = [[NSMutableDictionary alloc] initWithObjectsAndKeys:@"5",@"five",@"6",@"six",@"7",@"seven",@"8",@"eight", nil];
        [mulDict3 removeObjectsForKeys:@[@"five",@"eight",@"nine"]];
        NSLog(@"mulDict3 = %@", mulDict3);
        //重置字典对象
        [mulDict3 setDictionary:@{@"hello":@"1",@"world":@"3"}];
        NSLog(@"mulDict3 = %@", mulDict3);
        
    }
    return 0;
}