NSDictionary用法

使用

// NSDictionary
-(void)testNSDictionary{
    NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:@"value1",@"key1", @"value2", @"key2", nil];
    //得到词典的数量
    NSUInteger _count = [dictionary count];
    NSLog(@"词典的数量为:%lu", (unsigned long)_count);
    
    //得到词典中所有KEY值
    NSEnumerator * enumeratorKey = [dictionary keyEnumerator];
    //快速美剧遍历所有KEY值
    for(NSObject *object in enumeratorKey) {
        NSLog(@"遍历KEY的值:%@", object);
    }
    
    //得到词典中所有value值
    NSEnumerator * enumberatorValue = [dictionary objectEnumerator];
    //得到词典中d所有value值
    for(NSObject *object in enumberatorValue) {
        NSLog(@"遍历Value值：%@", object);
    }
    
    //通过KEY找到value
    NSObject *object = [dictionary objectForKey:@"key1"];
    
    if(object != nil) {
        NSLog(@"通过KEYd找到的value是：%@", object);
    }
}

结果

词典的数量为:2
遍历KEY的值:key1
遍历KEY的值:key2
遍历Value值：value1
遍历Value值：value2
通过KEYd找到的value是：value1

NSMutableDictionary

使用

// NSMutableDictionary
-(void)testNSMutableDictionary{
    //创建词典对象，初始化长度10
    NSMutableDictionary *dictinary = [NSMutableDictionary dictionaryWithCapacity:10];
    //向词典中动态添加数据
    [dictinary setObject:@"value1" forKey:@"key1"];
    [dictinary setObject:@"value2" forKey:@"key2"];
    
    //通过KEY找到value
    NSObject *object = [dictinary objectForKey:@"key1"];
    if(object != nil) {
        NSLog(@"通过KEY找到的value是:%@", object);
    }
    
}

结果

通过KEY找到的value是:value1