Objective C USES regular expressions for matching in iOS App development

There are three ways to achieve regular expression matching in iOS. Now record them all here:

1. Use NSPredicate (predicate) matching
For example, match valid mailbox:

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];

Predicate matching is flexible, but requires knowledge of predicates.

2. Use rangeOfString: option: direct search

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]); 
}

Setting NSRegularExpressionSearch in options means the position where the first result will be returned using a regular expression match.

3. Use regular expression classes

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]);
}

Using the system's regular expression class (NSRegularExpression) returns multiple matches.

Example:
1. Verify the mailbox

+ (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 is an Foundation class for queries, similar in principle and usage to where in SQL.

2. Verify your phone number

Simple judgment

+ (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];
}

It's simply a matter of determining the phone number format. In fact, the format of mobile phones is a bit complicated.

Detailed judgment method

// Regex determines the phone number format 
+ (BOOL)validatePhone:(NSString *)phone
{
    /**
    *  Mobile phone number 
    *  Mobile: 134[0-8],135,136,137,138,139,150,151,157,158,159,182,187,188
    *  Unicom: 130,131,132,152,155,156,185,186
    *  Telecommunication: 133,1349,153,180,189
    */
    NSString * MOBILE = @"^1(3[0-9]|5[0-35-9]|8[025-9])\\d{8}$";
    /**
         *  China Mobile: China Mobile
         * 134[0-8],135,136,137,138,139,150,151,157,158,159,182,187,188
         */
    NSString * CM = @"^1(34[0-8]|(3[5-9]|5[017-9]|8[278])\\d)\\d{7}$";
    /**
         *  China Unicom: China Unicom
         * 130,131,132,152,155,156,185,186
         */
    NSString * CU = @"^1(3[0-2]|5[256]|8[56])\\d{8}$";
    /**
         *  China Telecom: China Telecom
         * 133,1349,153,180,189
         */
    NSString * CT = @"^1((33|53|8[09])[0-9]|349)\\d{7}$";
    /**
         *  Mainland area fixed telephone and PHS 
         *  The area code: 010,020,021,022,023,024,025,027,028,029
         *  Number: 7 or 8 position 
         */
   // 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;
  }
}