// // 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; }
时间: 2024-10-07 13:07:50