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 = [nspredicatepredicateWithFormat:@"SELF MATCHES %@",regex];
BOOLisValid = [predicateevaluateWithObject: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
ottom:0px; padding-top:0px; padding-bottom:0px; font-size:14px; color:rgb(69,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。