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  1. Prepare
  2. Java
  3. Strings
  4. Valid Username Regular Expression
  5. Discussions

Valid Username Regular Expression

  • mahendra_mulmul1
     + 0 comments

    import java.util.Scanner;

    public class Solution { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n = Integer.parseInt(sc.nextLine()); // use nextLine() here

        String regex = "^[A-Za-z][A-Za-z0-9_]{7,29}$";

    for (int i = 0; i < n; i++) {
        String username = sc.nextLine(); 

        if (username.matches(regex)) {
            System.out.println("Valid");
        } else {
            System.out.println("Invalid");
        }
    }
    sc.close();
}

    }