iPhone从字符串中删除子字符串

Question

嗨,我有一个这样的字符串

NSString *str=@"1,2,3,4";

我必须动态删除任何字符.

对于前@"3"

Answer 1

NSString *str=@"1,2,3,4";
[str stringByReplacingOccurrencesOfString:@"3," withString:@""];

这将删除所有出现的@"3" str.

如果您只想删除第一次出现的@"3",:

NSString* str = @"1,2,3,4";
NSRange replaceRange = [str rangeOfString:@"3,"];
if (replaceRange.location != NSNotFound){
    NSString* result = [str stringByReplacingCharactersInRange:replaceRange withString:@""];
}

希望这可以帮助.

Answer 2

  NSString *str=@"1,2,3,4";
  int numberToRemove = 4;

 str = [str stringByReplacingOccurrencesOfString:[NSString stringWithFormat:@"%d",numberToRemove] withString:@""];
 str = [str stringByReplacingOccurrencesOfString:@",," withString:@","];

这会有所帮助.