ios - 与 ","分开？

Question

我像那样遍历数组。

NSArray *array = [[currentRaum raumattribute] allObjects];

    NSString *compositeString = [ [ NSString alloc ] init ];
    for( Raumattribute *attr in array ){
        compositeString = [ NSString stringWithFormat:@"%@ %@",compositeString, attr.attributname ];
    [raumAttributLabel setText:compositeString];

我想要这样的输出 ----> Cat,Dog,Mouse

但是如果我这样做:

compositeString = [ NSString stringWithFormat:@"%@ %@,",compositeString, attr.attributname ];

输出是猫，狗，老鼠，

或者如果我这样做:

compositeString = [ NSString stringWithFormat:@"%@ ,%@",compositeString, attr.attributname ];

输出它的,Cat,Dog,Mouse

有解决办法吗？

Answer 1

您可以使用数组的 valueForKey: 和 componentsJoinedByString: 方法来做到这一点:

NSString * compositeString =  [[array valueForKey:@"attributname"] componentsJoinedByString:@","]

valueForKey: 将为每个数组元素创建属性名称值数组

componentsJoinedByString: 将这些值连接成一个字符串，用逗号分隔