Regex

[Mary Cole]

Hi,

I want to find if a String has only special characters and no Alpha numberic characters...Can anybody please provide the Regex for this?

Thanks in advance

[Janeice DelVecchio]

I don't have a lot of experience with Regexes.... I might just iterate through the string and check each character with the Character.isLetterOrDigit() method.

I am interested to see what kind of responses come of this.... I always like to learn ways to "work smarter not harder"

[Ninad Kulkarni]

Do a search on regular expressions in JavaRanch forum you will find many posts related to this.
Refer Pattern & Regular Expressions
Predefined character classes : \W
POSIX character classes (US-ASCII only): \p{Punct}
Is that helpful for you to find special characters?

[Rob Spoor]

You can use [^ABCD] to find match anything but A, B, C or D. I'm sure you can use that.

[Mary Cole]

The thing is that I want to know if the String has only NON alpha numeric characters..am having problem in coming up with a regex for it.

[Rob Spoor]

If a number has only non-alphanumeric characters, it does not have any alphanumeric characters. Instead of checking if all characters are non-alphanumeric, check if at least one character is alphanumeric and then negate the result.

[Mary Cole]

   private static final Pattern p = Pattern.compile( "(^[A-Z,a-z,0-9])" );
public static void main( String[] args )
     {
     final String lookIn = "&&@)($@()$(*(@$+";		 
     //final String lookIn = "AADR #RWWDDSDSSFF";
     
     System.out.println("Value is "+match(lookIn));
     
     }

 

The above code is giving me false for bothe lookin values...don't know where am wrong

[Rob Spoor]

1) remove the , from your regex' character class. By adding them you specify that , is part of the character class, therefore you are disallowing , as well.

2) Your regex is only testing for one single character. Check out the quantifiers sections of java.util.regex.Pattern