版本

Xcode 8.2.1

一、不可变字典NSDictionary

字典就是，key和value成对相对应地存入dictionary。key为字符串，value为所有对象Object，可以是string、array等等。

    //创建:value1,key1,value2,key2...,(key和value成对出现)
    //value:OC的任何对象都可以，
    NSDictionary *dic11 = [NSDictionary dictionaryWithObjectsAndKeys:@"aabbb",@"1",@"dddeee",@"2",nil];
    NSLog(@"dic = %@",dic11);
    
    //key1:value1,key2:value2...
    //@{}只能用于创建不可变字典
    NSDictionary *dic1 = @{@"One":@"11",@"Two":@"22",@"Three":@"22"};
    NSLog(@"dic1 = %@",dic1);
    
    //通过key值访问value值
    NSString *strDic = [dic1 valueForKey:@"Two"];
    NSLog(@"strDic = %@",strDic);
    
    //访问value,dic [key]
    NSString *strDic1 = dic1[@"Two"];
    NSLog(@"strDic1 = %@",strDic1);
    
    //遍历字典，遍历key值
    NSArray *keyArr = [dic1 allKeys];
    for(NSString *keyin keyArr) {
        NSLog(@"key = %@",key);
    }
    
    //通过value,获取具有相同value的key array
    NSArray *keyArr1 = [dic1 allKeysForObject:@"22"];
    
    //遍历Value值,返回所有的Value值
    NSArray *valArr = [dic1 allValues];
    for(id valuein valArr) {
        NSLog(@"value = %@",value);
    }
    
    //默认遍历key值
    for(id objin dic1) {
        NSLog(@"obj = %@",dic1[obj]);
    }

NSArray栗子：

先创建一个plist文件,并取名dict3，等下我们将通过这个名字来查找内容：

1.jpg 2.jpg

填入key和value：

3.jpg

然后来到main方法：

int main(int argc, char * argv[]) {
    
    //@{}只能用于创建不可变字典(注意：先key后value)
    NSDictionary *dict1 = @{@"role":@"Invincible Eastern",@"age":@"30",@"sex":@"male&female"};
    NSLog(@"%@",dict1);
    
    //value:OC的任何对象都可以(注意：先value后key)
    NSDictionary *dict2 = [NSDictionary dictionaryWithObjectsAndKeys:@"the monkey king",@"role",@"500",@"age",@"male",@"sex", nil];
    NSLog(@"%@",dict2);
    
    //查plist文件
    NSDictionary *dict3 = [NSDictionary dictionaryWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"dict3" ofType:@"plist" ]];
    NSLog(@"%@",dict3);
    NSLog(@"%@",dict3[@"role"]);
    
    //访问value
    NSLog(@"%@",[dict2 valueForKey:@"age"]);
    NSLog(@"%@",[dict2 objectForKey:@"age"]);
    NSLog(@"%@",dict2[@"age"]);
    
    //遍历value
    NSArray *valArr = [dict2 allValues];
    for(id value in valArr){
        NSLog(@"value = %@",value);
    }
    
    //获取具有相同value的key array
    NSArray *keyArr1 = [dict2 allKeysForObject:@"500"];
    NSLog(@"500的key为%@",keyArr1);
    
    //遍历key
    NSArray *keyArr2 = [dict2 allKeys];
    for(id value in keyArr2){
        NSLog(@"key = %@",value);
    }
    
    //默认遍历keu
    for(id value in dict2){
        NSLog(@"obj = %@",dict2[value]);
    }
}

输出结果:

二、可变字典NSMutableDictionary

    //实例化一个空的可变字典
    NSMutableDictionary *dic2 = [NSMutableDictionary dictionary];
 //   NSMutableDictionary *dic2 = [[NSMutableDictionary alloc]init];
    
    //通过一个数组实例化一个可变字典
    NSMutableDictionary *dic3 = [NSMutableDictionary dictionaryWithObjects:@[@"1",@"2",@"3"] forKeys:@[@"One",@"Three",@"Three"]];
    NSLog(@"dic3 = %@",dic3);
    
    //添加元素(当字典内不存在此key值)
    [dic3 setObject:@"4" forKey:@"Four"];
    
    //修改value值(当字典内存在此key值)
    [dic3 setObject:@"11" forKey:@"One"];
    
    //通过key值获取value值
    NSString *rstr = [dic3 valueForKey:@"Two"];//dic3[@"Two"];
    
    //删除，删除键值对
    [dic3 removeObjectForKey:@"One"];
    
    //删除所有数组中含有的key值的键值对
    [dic3 removeObjectsForKeys:@[@"Four",@"Three"]];
    
    //删除所有键值对
    [dic3 removeAllObjects];

NSMutableDictionary栗子：

int main(int argc, char * argv[]) {
    
    //实例化一个可变字典
    NSMutableDictionary *dic1 = [NSMutableDictionary dictionary];
    //NSMutableDictionary *dic1 = [[NSMutableDictionary alloc]init];
    NSLog(@"dic1 = %@",dic1);
    
    //通过一个数组实例化一个可变字典
    NSMutableDictionary *dic2 = [NSMutableDictionary dictionaryWithObjects:@[@"Invincible Eastem",@"30"] forKeys:@[@"role",@"age"]];
    NSLog(@"dic2 = %@",dic2);
    
    //添加元素(当字典内不存在此key值)
    [dic2 setObject:@"male" forKey:@"sex"];
    NSLog(@"sex = %@",dic2);
    
    //修改value值(当字典内存在此key值)
    [dic2 setObject:@"female" forKey:@"sex"];
    NSLog(@"sex = %@",dic2);
    
    //通过key值获取value值
    NSLog(@"sex = %@",[dic2 valueForKey:@"sex"]);
    NSLog(@"sex = %@",dic2[@"sex"]);
    
    //删除键值对
    [dic2 removeObjectForKey:@"role"];
    [dic2 removeObjectsForKeys:@[@"role",@"age"]];
    
    //删除所有键值对
    [dic2 removeAllObjects];
    NSLog(@"sex = %@",dic2);
}

输出结果: