Valid Username Regular Expression | HackerRank Programming Solutions | HackerRank Java Solutions

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Link for the Problem – Valid Username Regular Expression – Hacker Rank Solution

Valid Username Regular Expression – Hacker Rank Solution

Objective

You are updating the username policy on your company’s internal networking platform. According to the policy, a username is considered valid if all the following constraints are satisfied:

• The username consists of  to  characters inclusive. If the username consists of less than 8 or greater than 30 characters, then it is an invalid username.

Problem Statement: Click Here

Valid Username Regular Expression – Hacker Rank Solution

import java.util.Scanner;

class UsernameValidator {
    public static final String regularExpression = "^[a-zA-Z][\\w]{7,29}$";
}

public class Solution {
    
    private static final Scanner scan = new Scanner(System.in);

    public static void main(String[] args) {
        int n = Integer.parseInt(scan.nextLine());
        while (n-- != 0) {
            String userName = scan.nextLine();

            if (userName.matches(UsernameValidator.regularExpression))
                System.out.println("Valid");
            else 
                System.out.println("Invalid");
        }
    }
}