NSDictionary使用小结（字典）

#import <Foundation/Foundation.h>
int main(int argc, const char * argv[])
{
@autoreleasepool {
//创建字典
NSDictionary *dic1 = [NSDictionary dictionaryWithObject:@"value" forKey:@"key"];
NSLog(@"dic1 :%@", dic1);
//创建多个字典
NSDictionary *dic2 = [NSDictionary dictionaryWithObjectsAndKeys:
@"value1", @"key1",
@"value2", @"key2",
@"value3", @"key3",
@"value4", @"key4",
nil];
NSLog(@"dic2 :%@", dic2);
//根据现有的字典创建字典
NSDictionary *dic3 = [NSDictionary dictionaryWithDictionary:dic2];
NSLog(@"dic3 :%@", dic3);
//根据key获取value
NSLog(@"key3 value :%@", [dic3 objectForKey:@"key3"]);
//获取字典数量
NSLog(@"dic count :%d", dic3.count);
//所有的键集合
NSArray *keys = [dic3 allKeys];
NSLog(@"keys :%@", keys);
//所有值集合
NSArray *values = [dic3 allValues];
NSLog(@"values :%@", values);
NSMutableDictionary *mutableDic = [[NSMutableDictionary alloc] initWithObjectsAndKeys:
@"mvalue1", @"mkey1",
@"mvalue2", @"mkey2", nil];
//添加现有的字典数据
[mutableDic addEntriesFromDictionary:dic3];
NSLog(@"mutableDic :%@",mutableDic);
//添加新的键值对象
[mutableDic setValue:@"set1" forKey:@"setKey1"];
NSLog(@"set value for key :%@",mutableDic);
//以新的字典数据覆盖旧的字典数据
[mutableDic setDictionary:dic2];
NSLog(@" set dictionary :%@",mutableDic);
//根据key删除value
[mutableDic removeObjectForKey:@"key1"];
NSLog(@"removeForkey :%@",mutableDic);
//快速遍历
for(id key in mutableDic) {
NSLog(@"key :%@ value :%@", key, [mutableDic objectForKey:key]);
}
//枚举遍历
NSEnumerator *enumerator = [mutableDic keyEnumerator];
id key = [enumerator nextObject];
while (key) {
NSLog(@"enumerator :%@", [mutableDic objectForKey:key]);
key = [enumerator nextObject];
}
//根据key数组删除元素
[mutableDic removeObjectsForKeys:keys];
NSLog(@"removeObjectsForKeys :%@",mutableDic);
[mutableDic removeAllObjects];
//删除所有元素
NSLog(@"remove all :%@", mutableDic);
}
return 0;
}

时间： 2024-08-25 18:11:57

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