NSString * reg = @\"[0-9]+\";//字符串正则表达式NSError *error = NULL;//错误对象NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:reg options:NSRegularExpressionCaseInsensitive error:&error];//匹配reg的正则表达式对象 

/**1 * 正则表达式匹配 * * @param string 在此字符串中匹配 * @param options 一般填0 * @param range 在此范围内匹配 * @param block 在block内会把匹配到的结果逐个返回NSTextCheckingResult，通过此对象的range属性可以查看匹配到的字符串的location和length，同过subString方法可以得到被匹配字符串 */- (void)enumerateMatchesInString:(NSString *)string options:(NSMatchingOptions)options range:(NSRange)range usingBlock:(void (^)(NSTextCheckingResult * __nullable result, NSMatchingFlags flags, BOOL *stop))block; /**2 * 正则表达式匹配 * * @param string 在此字符串中匹配 * @param options 一般填0 * @param range 在此范围内匹配 * @param block 返回数组，数组内是每个匹配到的NSTextCheckingResult */- (NSArray<NSTextCheckingResult *> *)matchesInString:(NSString *)string options:(NSMatchingOptions)options range:(NSRange)range; /**3 * 正则表达式匹配 * * @param string 在此字符串中匹配 * @param options 一般填0 * @param range 在此范围内匹配 * @param block 返回匹配到的个数 */- (NSUInteger)numberOfMatchesInString:(NSString *)string options:(NSMatchingOptions)options range:(NSRange)range; /**4 * 正则表达式匹配 * * @param string 在此字符串中匹配 * @param options 一般填0 * @param range 在此范围内匹配 * @param block 返回第一次匹配到的NSTextCheckingResult对象 */- (nullable NSTextCheckingResult *)firstMatchInString:(NSString *)string options:(NSMatchingOptions)options range:(NSRange)range; /**5 * 正则表达式匹配 * * @param string 在此字符串中匹配 * @param options 一般填0 * @param range 在此范围内匹配 * @param block 返回第一次匹配到的NSTextCheckingResult对象的range */- (NSRange)rangeOfFirstMatchInString:(NSString *)string options:(NSMatchingOptions)options range:(NSRange)range;3.NSString //- (NSRange)rangeOfString:(NSString *)searchString options:(NSStringCompareOptions)mask;//- (NSRange)rangeOfString:(NSString *)searchString options:(NSStringCompareOptions)mask range:(NSRange)searchRange;//匹配文本-(void)matchIn{ NSString *searchText = @\"rangeOf77Str88ing\"; //只能匹配一次 NSRange range = [searchText rangeOfString:@\"[0-9]+\" options:NSRegularExpressionSearch]; //拿到匹配结果 if (range.location != NSNotFound) { NSString * searchString= [searchText substringWithRange:range]; NSLog(@\"range.location = %lu range.length = %lu\", (unsigned long)range.location,(unsigned long)range.length); NSLog(@\"String = %@\",searchString); }else{ NSLog(@\"没有匹配\"); }} 4、正则表达式示例代码 
NSString *summaryString = [NSString stringWithFormat:@\"对%@题 错%@题 | 任务正确率%@ | 作业平均正确率%@\", questionRight, questionWrong, questionRate, taskRate];
NSMutableAttributedString *summaryAttributString = [[NSMutableAttributedString alloc] initWithString:summaryString];
// 正则匹配,匹配数字和百分号
NSString *reg = @\"[0-9]+|%\";
NSError *error = nil;
NSRegularExpression *regex = [[NSRegularExpression alloc] initWithPattern:reg options:NSRegularExpressionCaseInsensitive error:&error];
NSArray *array = [regex matchesInString:summaryString options:0 range:NSMakeRange(0, summaryString.length)];
if (array.count) {
for (int i = 0; i < array.count; i++) {
NSTextCheckingResult *result = array[i];
NSRange range = result.range;
[summaryAttributString addAttribute:NSForegroundColorAttributeName value:[UIColor colorWithHexString:@\"#e71419\"] range:range];
}
}
self.summaryLabel.attributedText = summaryAttributString;

//验证是否存在-(BOOL)validateRegular:(NSString * )regular matchText:(NSString *)text;{ 
//正则表达式格式 
//NSString* regular=@\"^1[0-9]{6}$\"; 
//创建谓词 
NSPredicate *numberPre = [NSPredicate predicateWithFormat:@\"SELF MATCHES %@\",regular]; 
//匹配字符串，若能匹配返回YES，否则返回NO； 
BOOL isMatch = [numberPre evaluateWithObject:text]; 
return isMatch;}