Check if NSString contains a special character and number

Question

I need to check if a string contains one uppercase letter, one lowercase letter, one integer and one special character. How can i check?

Answer 1

Without any additional frameworks:

NSCharacterSet * set = [[NSCharacterSet characterSetWithCharactersInString:@"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"] invertedSet]; if ([aString rangeOfCharacterFromSet:set].location != NSNotFound) { NSLog(@"This string contains illegal characters."); } 

You can also use regex (this syntax is from RegexKitLite: http://regexkit.sourceforge.net ):

 if ([aString isMatchedByRegex:@"[^a-zA-Z0-9]"]) { NSLog(@"This string contains illegal characters."); } 

Answer 2

Found a slightly better implementation. Amish's Better Answer

 - (BOOL)isValidString:(NSString *)string { return [string rangeOfCharacterFromSet:[NSCharacterSet uppercaseLetterCharacterSet]].location != NSNotFound && [string rangeOfCharacterFromSet:[NSCharacterSet lowercaseLetterCharacterSet]].location != NSNotFound && [string rangeOfCharacterFromSet:[NSCharacterSet decimalDigitCharacterSet]].location != NSNotFound; } 

Answer 3

Maulik's answer is incorrect. This will check for anything OTHER than any alphanumeric character, but does not guarantee that there is one uppercase letter, one lowercase letter and one whole. In fact, you need to do 3 checks to check each constraint.

 NSCharacterSet *lowerCaseChars = [NSCharacterSet characterSetWithCharactersInString:@"abcdefghijklmnopqrstuvwxyz"]; NSCharacterSet *upperCaseChars = [NSCharacterSet characterSetWithCharactersInString:@"ABCDEFGHIJKLKMNOPQRSTUVWXYZ"]; NSCharacterSet *numbers = [NSCharacterSet characterSetWithCharactersInString:@"0123456789"]; if ([aString rangeOfCharacterFromSet:lowerCaseChars].location == NSNotFound || [aString rangeOfCharacterFromSet:upperCaseChars].location = NSNotFound || [aString rangeOfCharacterFromSet:numbers].location == NSNotFound) { NSLog(@"This string contains illegal characters"); } 

Answer 4

For Arabic / English

 NSString *regEx = @"^([a-zA-Z0-9\u0600-\u06ff](\\-|\\_|\\.|\\ )?)+$"; NSPredicate *regExPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regEx]; BOOL myStringMatchesRegEx = [regExPredicate evaluateWithObject: self.text]; if (!myStringMatchesRegEx) return NO; 

Answer 5

Here is what I will do. Create regular expressions for each condition that you need to check if the corresponding value is present.

i.e. A regular expression to check if it has one uppercase letter, one lowercase letter, one integer and one special character, etc.

and then use the same line to check for each regular expression, if all of them return true, you have a winner, if not, then the line does not meet your criteria.

// Example for Validating UpperCaseLetter does the same for everyone else with the appropriate regular expression.

 -(BOOL) validateOneUpperCaseLetter:(NSString *)string { if ((string == nil) || ([string isEqualToString: @""])) { return NO; } // Change this regEx to one you needed. // this one validates for the "name". NSString *regEx = @"^[a-zA-Z]+(([\\'\\,\\.\\ -][a-zA-Z])?[a-zA-Z]\\s*)*$"; NSPredicate *regExPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regEx]; BOOL myStringMatchesRegEx = [regExPredicate evaluateWithObject: string]; if (!myStringMatchesRegEx) { return NO; } return YES;}