java regex validate alphanumeric

by

Regular expression to accept alphanumeric only

^[a-zA-Z0-9]+$

This regular expression refers to a pattern which accepts all lower and upper case characters, and digits only.

Example

package com.w3schools;
 
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
public class RegexTest {
	private static final String PATTERN = "^[a-zA-Z0-9]+$";
	public static void main(String args[]){ 
		List<String> names = new ArrayList<String>();	       
		names.add("Jai"); 
		names.add("Jai12"); 
		names.add("Jai12-");
 
		Pattern pattern = Pattern.compile(PATTERN);
		for (String name : names){
		  Matcher matcher = pattern.matcher(name);
		  System.out.println(matcher.matches());
		}
	}
}

Output

true
true
false