NSDictionary使用小结

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;

}

//打印——————————————————————————

dic1 :{

key = value;

}

dic2 :{

key1 = value1;

key2 = value2;

key3 = value3;

key4 = value4;

}

dic3 :{

key1 = value1;

key2 = value2;

key3 = value3;

key4 = value4;

}

key3 value :value3

dic count :4

keys :(

key2,

key3,

key1,

key4

)

values :(

value2,

value3,

value1,

value4

)

mutableDic :{

key1 = value1;

key2 = value2;

key3 = value3;

key4 = value4;

mkey1 = mvalue1;

mkey2 = mvalue2;

}

set value for key :{

key1 = value1;

key2 = value2;

key3 = value3;

key4 = value4;

mkey1 = mvalue1;

mkey2 = mvalue2;

setKey1 = set1;

}

set dictionary :{

key1 = value1;

key2 = value2;

key3 = value3;

key4 = value4;

}

removeForkey :{

key2 = value2;

key3 = value3;

key4 = value4;

}

key :key4 value :value4

key :key2 value :value2

key :key3 value :value3

enumerator :value4

enumerator :value2

enumerator :value3

removeObjectsForKeys :{

}

remove all :{

}