Simple Java Loop Question

Question

Assume that the int variables i and j have been declared, and that n has been declared and initialized.

Using for loops (you may need more than one), write code that will cause a triangle of asterisks of size n to be output to the screen.

For example, if the value of n is 4, the output should be

 *
 **
 ***
 ****

Answer 1

I won't do your homework, so here is a hint:

• The first line is always 1 element long.
• The last line is always N elements long.
• The are a total of N lines.

Surely, with the above, you can create the necessary program.

Answer 2

Incase you're in school/college and more interested in getting some, more power to you buddy:

for(int i = 0; i < n; i++)
{
    for(int j = 0; j <= i; j++)
        System.out.print("*");
    System.out.println();
}

Answer 3

    for(int i = 0; i < n; i++){
        for(int j = 0; j <= i; j++)
            System.out.print("*");
        System.out.println();
    }

Answer 4

Just for fun - single for-loop solution:

public void doIt(int n) {
  String temp = String.copyValueOf(char[n]);
  for (int i = 1; i <= n; i++)
    System.out.println(temp.substring(n-i).replace((char) 0, 'x'));
}

And some recursion - zero for-loop solution:

public void doItAgain(int n, String display) {
  if (n==0) return;
  System.out.println(display);
  doItAgain(n-1, display+'x');
}

(call it with doItAgain(4,"x") for your example)