如何循环 NSString N 次？

Question

如何将字符串循环 9 次？ (z x c v b n z x c)

NSString *fl = @"zxcvbn";

Answer 1

这是一个快速而粗略的片段：

NSString *string = @"abcdef";
NSString *letter = nil;
int n = 9;
for (int index = 0; index < n; index++) {
    // start over if it's more than the length
    int currentIndex = index % string.length;

    letter = [string substringWithRange:NSMakeRange(currentIndex, 1)];

    NSLog(@"letter: %@", letter);
}

如果你想要一个带有详细解释的低级示例check this out。

Answer 2

除了使用substringWithRange（其中returns一个NSString），还可以使用characterAtIndex获取字符值：

NSInteger n = 9;

for (NSInteger index = 0; index < n; index++) {
    unichar character = [fl characterAtIndex:index % fl.length];

    // do something with `character`, e.g.
    //
    // if (character == 'z') { ... } 
}

如何循环 NSString N 次？

How do I loop through NSString N number of times?

objective-c

nsstring

ios