Regex validation help

[deAppel]

Hi,

I'm new with regex and i wanted to ask how to properly validate a string using regex?

I created a small demo here:

Code

GeSHi (java):
class RegexString {
	public static void main(String[] args){
		String txt="abCD";
		String re1="[a-zA-Z]*";		
		Pattern p = Pattern.compile(re1,Pattern.CASE_INSENSITIVE | Pattern.DOTALL);
 
		Matcher m = p.matcher(txt);
		if (m.find()){
			String text=m.group(0);	
			System.out.print("String: "+text.toString());
		}
		else{
			System.out.print("Number");
		}
	}
}
Created by GeSHI 1.0.7.20

Although it prints out the text i can't seem to "catch" a non string value and do something with it. How can i go to the else when the entered text in the txt string does not matches [a-zA-Z] ?

Thanks,

Ark

[deAppel]

Nevermind, its fixed. Instead of find() , I was recommended to use matches()

Code

GeSHi (java):
import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
class RegexString {
	public static void main(String[] args){
		String txt="1234AB";	
		String re1="^[0-9]{4}[a-z|A-Z]{2}$";	
 
		Pattern p = Pattern.compile(re1);
		Matcher m = p.matcher(txt);
		if (m.matches()){
			String text=m.group(0);	
			System.out.print("Postcode: "+text.toString());
		}
		if (!m.matches()){	
			System.out.print("Not a valid postcode.");
		}
	}
}
 
Created by GeSHI 1.0.7.20

[Arkie]

An email validator using regex:

Code

GeSHi (java):
import java.util.regex.*;
 
class regexSample 
{
   public static void main(String args[]) 
   {
      //Input the string for validation
      String email = "xyz@hotmail.com";
 
      //Set the email pattern string
      Pattern p = Pattern.compile(".+@.+\\.[a-z]+");
 
      //Match the given string with the pattern
      Matcher m = p.matcher(email);
 
      //check whether match is found 
      boolean matchFound = m.matches();
 
      if (matchFound)
        System.out.println("Valid Email Id.");
      else
        System.out.println("Invalid Email Id.");
   }
}
Created by GeSHI 1.0.7.20

http://www.devx.com/tips/Tip/28334