您需要使用 NSRegularExpression 类.

You need to use NSRegularExpression class.

文档中启发的示例:

NSString *yourString = @"";
NSError *error = NULL;
NSRegularExpression *regex = [NSRegularExpression         
    regularExpressionWithPattern:@"(NS|UI)+(\w+)"
    options:NSRegularExpressionCaseInsensitive
    error:&error];
[regex enumerateMatchesInString:yourString options:0 range:NSMakeRange(0, [yourString length]) usingBlock:^(NSTextCheckingResult *match, NSMatchingFlags flags, BOOL *stop){
    // your code to handle matches here
}];