Question

我想打印一个播放列表。以下是我将如何在python中执行此操作：

playlist = ['Classical Song', 'Rock Song', 'New Song']
for num, item in enumerate(playlist):
    print '%s) %s' % (num+1, item)

1) Classical Song
2) Rock Song
3) New Song

我如何在Objective-C中做同样的事情？以下是我到目前为止的情况：

NSArray *playlist = @[@"Classical Song", @"Rock Song", @"New Song"];
for (NSString *item in playlist) {
    NSLog(@"?) %@", item);
}

2014-08-23 15:56:34.421 Music[16332:303] ?) Classical Song
2014-08-23 15:56:34.423 Music[16332:303] ?) Rock Song
2014-08-23 15:56:34.423 Music[16332:303] ?) New Song

如何更改上面的内容以获取枚举循环中的数字？

Answer 1

for循环中没有提供索引，但是有一个方法enumerateObjectsUsingBlock：就是这样。

NSArray *playlist = @[@"Classical Song", @"Rock Song", @"New Song"];
[playlist enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
       NSLog(@"%ld) %@", idx+1, obj);
}];

在目标C中枚举的等效python

1 个答案: