iOS 正则表达式详解

一、系统自带正则表达式用法

除了正则可以用,还有NSScanner这个类可以达到某些相同的效果

1、创建正则表达式对象

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 

2、正则表达式对象可调用的方法

- (void)enumerateMatchesInString:(NSString *)string options:(NSMatchingOptions)options range:(NSRange)range usingBlock:(void (^)(NSTextCheckingResult * __nullable result, NSMatchingFlags flags, BOOL *stop))block; - (NSArray *)matchesInString:(NSString *)string options:(NSMatchingOptions)options range:(NSRange)range; - (NSUInteger)numberOfMatchesInString:(NSString *)string options:(NSMatchingOptions)options range:(NSRange)range; - (nullable NSTextCheckingResult *)firstMatchInString:(NSString *)string options:(NSMatchingOptions)options range:(NSRange)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;

5.谓词

//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;}

以上所述是小编给大家介绍的iOS正则表达式，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对考高分网网站的支持！