ios的正則表達式（續）

下面，列舉一個匹配6-15個由字母/數字組成的字符串的正則表達式，來看看 NSPredicate 的具體使用：

1	NSString * regex        = @"(^[A-Za-z0-9]{6,15}$)";

2	NSPredicate * pred      = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];

3	BOOL isMatch            = [pred evaluateWithObject:@"123456ABCde"];

01	下面是一些常用的正則表達式

02

//郵箱

03	+ (BOOL) validateEmail:(NSString *)email

04

{

05	NSString *emailRegex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}";

06	NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegex];

07	return[emailTest evaluateWithObject:email];

08

}

09

10

11

//手機號碼驗證

12	+ (BOOL) validateMobile:(NSString *)mobile

13

{

14	//手機號以13， 15，18開頭，八個 \d 數字字符

15	NSString *phoneRegex = @"^((13[0-9])|(15[^4,\\D])|(18[0,0-9]))\\d{8}$";

16	NSPredicate *phoneTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",phoneRegex];

17	return[phoneTest evaluateWithObject:mobile];

18

}

19

20

21

//車牌號驗證

22	+ (BOOL) validateCarNo:(NSString *)carNo

23

{

24	NSString *carRegex = @"^[\u4e00-\u9fa5]{1}[a-zA-Z]{1}[a-zA-Z_0-9]{4}[a-zA-Z_0-9_\u4e00-\u9fa5]$";

25	NSPredicate *carTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",carRegex];

26	NSLog(@"carTest is %@",carTest);

27	return[carTest evaluateWithObject:carNo];

28

}

29

30

31

//車型

32	+ (BOOL) validateCarType:(NSString *)CarType

33

{

34	NSString *CarTypeRegex = @"^[\u4E00-\u9FFF]+$";

35	NSPredicate *carTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",CarTypeRegex];

36	return[carTest evaluateWithObject:CarType];

37

}

38

39

40

//用戶名

41	+ (BOOL) validateUserName:(NSString *)name

42

{

43	NSString *userNameRegex = @"^[A-Za-z0-9]{6,20}+$";

44	NSPredicate *userNamePredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", userNameRegex];

45	BOOLB = [userNamePredicate evaluateWithObject:name];

46

returnB;

47

}

48

49

50

//密碼

51	+ (BOOL) validatePassword:(NSString *)passWord

52

{

53	NSString *passWordRegex = @"^[a-zA-Z0-9]{6,20}+$";

54	NSPredicate *passWordPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", passWordRegex];

55	return[passWordPredicate evaluateWithObject:passWord];

56

}

57

58

59

//暱稱

60	+ (BOOL) validateNickname:(NSString *)nickname

61

{

62	NSString *nicknameRegex = @"^[\u4e00-\u9fa5]{4,8}$";

63	NSPredicate *passWordPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",                                       nicknameRegex];

64	return[passWordPredicate evaluateWithObject:nickname];

65

}

66

67

68

//身份證號

69	+ (BOOL) validateIdentityCard: (NSString *)identityCard

70

{

71

BOOLflag;

72	if(identityCard.length <= 0) {

73	flag = NO;

74	returnflag;

75

}

76	NSString *regex2 = @"^(\\d{14}|\\d{17})(\\d|[xX])$";

77	NSPredicate *identityCardPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex2];

78	return[identityCardPredicate evaluateWithObject:identityCard];

79

}

其實iOS中有三種方式來實現正則表達式的匹配。現在將他們都記錄在這裏：

1.利用NSPredicate（謂詞）匹配

例如匹配有效郵箱：

NSString ＊email ＝ @“[email protected]”；

    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];

謂詞匹配比較靈活，但是需要有謂詞的相關知識。

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中設定NSRegularExpressionSearch就是表示利用正則表達式匹配，會返回第一個匹配結果的位置。

3.使用正則表達式類

    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]);

    }

使用系統的正則表達式類（NSRegularExpression）會返回匹配的多個結果。

小結：

第一種匹配需要學習NSPredicate的寫法，需要查閱蘋果相關技術文檔；如果只關心第一個匹配的結果，第二種匹配較爲簡潔；如果需要匹配多個結果，同時匹配多次，第三種方式效率會更高。