Question

Hello I try to convert my java function in objective-c for iphone

Java:

    public int substrCount(String str, String needle) {
    int count = 0;
    int index = -needle.length();
    while ((index = str.indexOf(needle, index + needle.length())) != -1) {
        count++;
    }
    return count;
}

Iphone:

-(int)substrCount:(NSString *) str withSearch:(NSString *) needle
{
  NSRange lastIndex;
  lastIndex.length = [str length];
  NSInteger count =0;

  while(lastIndex.length != -1){
    lastIndex = [str rangeOfString:needle options:NSCaseInsensitiveSearch range:lastIndex];
    //lastIndex = str.indexOf(needle,lastIndex);

    if( lastIndex.length != -1){
        NSLog(@"+1");
        count ++;
    }
  }
}

But it’s so hard, I don’t understand when I can make it.

Maybe there are better solution existing? I don’t have found anything :/

Sorry for my bad english !

Answer 1

I’d probably never write this code in production, but You could simply ask:

[[str1 componentsSeparatedByString:str2] count] – 1;

The result of that expression will be an integer representing the number of times str2 was found in str1.

However, the problem with your code is rangeOfString: returns NSNotFound if it can’t find the substring, not -1.