NSString 中子字符串的出现次数? [英] Number of occurrences of a substring in an NSString?

问题描述

如何获取 NSString(例如，@"cake")在较大的 NSString(例如，@"Cheesecake, apple cake, and cherry馅饼")?

How can I get the number of times an NSString (for example, @"cake") appears in a larger NSString (for example, @"Cheesecake, apple cake, and cherry pie")?

我需要对很多字符串执行此操作，因此无论我使用什么方法都需要相对较快.

I need to do this on a lot of strings, so whatever method I use would need to be relatively fast.

谢谢！

推荐答案

这没有经过测试，但应该是一个好的开始.

This isn't tested, but should be a good start.

NSUInteger count = 0, length = [str length];
NSRange range = NSMakeRange(0, length); 
while(range.location != NSNotFound)
{
  range = [str rangeOfString: @"cake" options:0 range:range];
  if(range.location != NSNotFound)
  {
    range = NSMakeRange(range.location + range.length, length - (range.location + range.length));
    count++; 
  }
}

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