java

package CodeAcademy_5_Loops_And_Arrays;

import java.util.Scanner;

public class DrawSquareDemo
{
  public static void main(String[] args)
  {
    Scanner scanner = new Scanner(System.in);
    System.out.println("Enter n: ");
    int n = scanner.nextInt();


    while (!(n > 0 && n <= 30)) {
      System.out.println("N, not in range, it should be (0,30]: ");
        n = scanner.nextInt();
    }

    int[][] arr = new int[n][n];

    for (int col = 0; col < n; col++) {
      for (int row = 0; row < n; row++) {
        System.out.print("# ");
      }
      System.out.println();
    }
  }
}