java - how to automatically populate a 2d array with numbers

Question

Hi i am trying to auto populate a 2d array based on user input. The user will enter 1 number, this number will set the size of the 2d array. i then want to print out the numbers of the array. for example , if the user enters the number 4 . the 2d array will be 4 rows by 4 colums, and should contain the number 1 to 16, and print out as follows.

1-2-3-4
5-6-7-8
9-10-11-12
13-14-15-16

But i am struggling to think of the right statement that will do this. for the moment my code just prints out a 2d array containing *.

Has anyone any ideas how i could print out the numbers , i'm really stuck. my code follows:

public static void main(String args[]){

    Scanner input = new Scanner(System.in);
    System.out.println("Enter room length");

    int num1 = input.nextInt();
    int num2 = num1;
    int length = num1 * num2;
    System.out.println("room "+num1+"x"+num2+"="+length);

    int[][] grid = new int[num1][num2];

    for(int row=0;row<grid.length;row++){   
        for(int col=0;col<grid[row].length;col++){
            System.out.print("*");  
        }
        System.out.println();
    }
}

Answer 1

Read n value,

int[][] arr = new int[n][n];
int inc=1;
for(int i=0;i<n;i++)
for(int j=0;j<n;j++)
{
arr[i][j]=inc;
inc++;
}