iOS中用正则表达式找出匹配的内容

// regularExpress:正则表达式     desString:被查找的字符串
+ (NSString *)matchRegularExpress:(NSString *)regularExpress andDesString:(NSString *)desString
{
    NSError *error;
    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:regularExpress options:0 error:&error];
    if (regex != nil) {
        NSTextCheckingResult *firstMatch=[regex firstMatchInString:desString options:0 range:NSMakeRange(0, [desString length])];
        if (firstMatch) {
            NSRange resultRange = [firstMatch rangeAtIndex:0];
            NSString *result=[desString substringWithRange:resultRange];
            return result;
        }
    }
    return nil;
}

祝您愉快开心 ^_^