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oc 正则表达式

2017年08月13日 ⁄ 综合 ⁄ 共 4002字 ⁄ 字号 评论关闭

iOS 中可以通过 NSPredicate 来处理正则表达式。相关资料如下:
NSPredicate 苹果官方文档:
http://developer.apple.com/documentation/Cocoa/Conceptual/Predicates/predicates.html

Predicate format strings:
http://developer.apple.com/documentation/Cocoa/Conceptual/Predicates/Articles/pSyntax.html

ICU 正则表达式规则:
http://www.icu-project.org/userguide/regexp.html


在 iOS 中,我们使用 NSPredicate 的字符串比较功能来进行正则表达式处理,其比较关键字为:MATCHES

下面,列举一个匹配6-15个由字母/数字组成的字符串的正则表达式,来看看 NSPredicate 的具体使用:

NSString * regex        = @"(^[A-Za-z0-9]{6,15}$)";  
NSPredicate * pred      = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];  
BOOL isMatch            = [pred evaluateWithObject:@"123456ABCde"];  

下面是一些常用的正则表达式

//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];  
}  
  
  
//手机号码验证  
+ (BOOL) validateMobile:(NSString *)mobile  
{  
    //手机号以13, 15,18开头,八个 \d 数字字符  
    NSString *phoneRegex = @"^((13[0-9])|(15[^4,\\D])|(18[0,0-9]))\\d{8}$";  
    NSPredicate *phoneTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",phoneRegex];  
    return [phoneTest evaluateWithObject:mobile];  
}  
  
  
//车牌号验证  
+ (BOOL) validateCarNo:(NSString *)carNo  
{  
    NSString *carRegex = @"^[\u4e00-\u9fa5]{1}[a-zA-Z]{1}[a-zA-Z_0-9]{4}[a-zA-Z_0-9_\u4e00-\u9fa5]$";  
    NSPredicate *carTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",carRegex];  
    NSLog(@"carTest is %@",carTest);  
    return [carTest evaluateWithObject:carNo];  
}  
  
  
//车型  
+ (BOOL) validateCarType:(NSString *)CarType  
{  
    NSString *CarTypeRegex = @"^[\u4E00-\u9FFF]+$";  
    NSPredicate *carTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",CarTypeRegex];  
    return [carTest evaluateWithObject:CarType];  
}  
  
  
//用户名  
+ (BOOL) validateUserName:(NSString *)name  
{  
    NSString *userNameRegex = @"^[A-Za-z0-9]{6,20}+$";  
    NSPredicate *userNamePredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",userNameRegex];  
    BOOL B = [userNamePredicate evaluateWithObject:name];  
    return B;  
}  
  
  
//密码  
+ (BOOL) validatePassword:(NSString *)passWord  
{  
    NSString *passWordRegex = @"^[a-zA-Z0-9]{6,20}+$";  
    NSPredicate *passWordPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",passWordRegex];  
    return [passWordPredicate evaluateWithObject:passWord];  
}  
  
  
//昵称  
+ (BOOL) validateNickname:(NSString *)nickname  
{  
    NSString *nicknameRegex = @"^[\u4e00-\u9fa5]{4,8}$";  
    NSPredicate *passWordPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",nicknameRegex];  
    return [passWordPredicate evaluateWithObject:nickname];  
}  
  
  
//身份证号  
+ (BOOL) validateIdentityCard: (NSString *)identityCard  
{  
    BOOL flag;  
    if (identityCard.length <= 0) {  
        flag = NO;  
        return flag;  
    }  
    NSString *regex2 = @"^(\\d{14}|\\d{17})(\\d|[xX])$";  
    NSPredicate *identityCardPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regex2];  
    return [identityCardPredicate evaluateWithObject:identityCard];  
}

其实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。

小结:

第一种匹配需要学习NSPredicate的写法,需要查阅苹果相关技术文档;如果只关心第一个匹配的结果,第二种匹配较为简洁;如果需要匹配多个结果,同时匹配多次,第三种方式效率会更高。

转载自:http://blog.csdn.net/houwenfu/article/details/17650479

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