iOS中有三种方式来实现正则表达式的匹配。现在将他们都记录在这里：

1.利用NSPredicate（谓词）匹配
例如匹配有效邮箱：

NSString ＊email ＝ @“nijino_saki@163.com”； NSString *regex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+//.[A-Za-z]{2,4}"; NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex]; BOOL isValid = [predicate evaluateWithObject:email];

谓词匹配比较灵活，但是需要有谓词的相关知识。

2.利用rangeOfString：option：直接查找

NSString *searchText = @"// Do any additional setup after loading the view, typically from a nib.";  NSRange range = [searchText rangeOfString:@"(?:[^,])*//." options:NSRegularExpressionSearch];  if (range.location != NSNotFound) {   NSLog(@"%@", [searchText substringWithRange:range]); }

options中设定NSRegularExpressionSearch就是表示利用正则表达式匹配，会返回第一个匹配结果的位置。

3.使用正则表达式类

NSString *searchText = @"// Do any additional setup after loading the view, typically from a nib.";  NSError *error = NULL;NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"(?:[^,])*//." options:NSRegularExpressionCaseInsensitive error:&error];NSTextCheckingResult *result = [regex firstMatchInString:searchText options:0 range:NSMakeRange(0, [searchText length])];if (result) {  NSLog(@"%@/n", [searchText substringWithRange:result.range]);}

使用系统的正则表达式类（NSRegularExpression）会返回匹配的多个结果。

实例：
1.验证邮箱

+ (BOOL)validateEmail:(NSString *)email{  NSString *emailRegex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+//.[A-Za-z]{2,4}";  NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegex];  return [emailTest evaluateWithObject:email];}

NSPredicate是一个Foundation类，是用来查询的，原理和用法都类似于SQL中的where。

2.验证手机号

简单的判断方法

+ (BOOL)validatePhone:(NSString *)phone{  NSString *phoneRegex = @"1[3|5|7|8|][0-9]{9}";  NSPredicate *phoneTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", phoneRegex];  return [phoneTest evaluateWithObject:phone];}

这只是简单地判断手机号格式。其实手机的格式还是有一点复杂的。

详细的判断方法

//正则判断手机号码格式+ (BOOL)validatePhone:(NSString *)phone{    /**    * 手机号码    * 移动：134[0-8],135,136,137,138,139,150,151,157,158,159,182,187,188    * 联通：130,131,132,152,155,156,185,186    * 电信：133,1349,153,180,189    */    NSString * MOBILE = @"^1(3[0-9]|5[0-35-9]|8[025-9])//d{8}$";    /**         * 中国移动：China Mobile         * 134[0-8],135,136,137,138,139,150,151,157,158,159,182,187,188         */    NSString * CM = @"^1(34[0-8]|(3[5-9]|5[017-9]|8[278])//d)//d{7}$";    /**         * 中国联通：China Unicom         * 130,131,132,152,155,156,185,186         */    NSString * CU = @"^1(3[0-2]|5[256]|8[56])//d{8}$";    /**         * 中国电信：China Telecom         * 133,1349,153,180,189         */    NSString * CT = @"^1((33|53|8[09])[0-9]|349)//d{7}$";    /**         * 大陆地区固话及小灵通         * 区号：010,020,021,022,023,024,025,027,028,029         * 号码：七位或八位         */   // NSString * PHS = @"^0(10|2[0-5789]|//d{3})//d{7,8}$";   NSPredicate *regextestmobile = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", MOBILE];   NSPredicate *regextestcm = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CM];   NSPredicate *regextestcu = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CU];   NSPredicate *regextestct = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CT];  if (([regextestmobile evaluateWithObject:phone] == YES)  || ([regextestcm evaluateWithObject:phone] == YES)  || ([regextestct evaluateWithObject:phone] == YES)  || ([regextestcu evaluateWithObject:phone] == YES))  {    if([regextestcm evaluateWithObject:phone] == YES) {     NSLog(@"China Mobile");    } else if([regextestct evaluateWithObject:phone] == YES) {     NSLog(@"China Telecom");    } else if ([regextestcu evaluateWithObject:phone] == YES) {     NSLog(@"China Unicom");    } else {     NSLog(@"Unknow");    }    return YES;  }  else   {    return NO;  }}