## Algorithm

Problem Name: Valid Username Regular Expression

In this HackerRank Functions in Java programming problem solution,

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 8 to 30 characters inclusive. If the username consists of less than 8 or greater than 30 characters, then it is an invalid username.
• The username can only contain alphanumeric characters and underscores (_). Alphanumeric characters describe the character set consisting of lowercase characters [a -z], uppercase characters [A - Z], and digits [0 - 9]
• The first character of the username must be an alphabetic character, i.e., either lowercase character [a -z] or uppercase character [A - Z].

Input Format

The first line of input contains an integer n , describing the total number of usernames. Each of the next n , describing the total number of usernames. Each of the next

• 1 <= n <= 100
• The username consists of any printable characters.

Output Format

For each of the usernames, the locked stub code prints Valid if the username is valid; otherwise Invalid each on a new line.

Sample Input 0

8
Julia
Samantha
Samantha_21
1Samantha
Samantha?10_2A
JuliaZ007
Julia@007
_Julia007


Sample Output 0

Invalid
Valid
Valid
Invalid
Invalid
Valid
Invalid
Invalid


Explanation 0

Refer diagram in the challenge statement.

## Code Examples

### #1 Code Example with Java Programming

Code - Java Programming


import java.util.Scanner;

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) {