Java program to print triangle or reverse triangle using any character

Java program to print Triangle pattern using ‘star’ or any character :

In this tutorial, we will show you how to print a Triangle in Java. We can print the Triangle using any character like *,&,$ etc.

Sample program to print a Triangle in Java :

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int size = 0;
        Character c;

        System.out.println("Enter height of the triangle : ");
        size = sc.nextInt();

        System.out.println("Which character you want to use : ");
        c = sc.next().charAt(0);

        int i, j, k;

        for (i = 0; i < size + 1; i++) {
            for (j = size; j > i; j--) {
                System.out.print(" ");
            }
            for (k = 0; k < (2 * i - 1); k++) {
                System.out.print(c);
            }
            System.out.println();
        }

    }
}

Output :

You need to enter the height of a triangle and the character you want to use for the triangle. It will then print the triangle like below :

Enter height of the triangle :
5
Which character you want to use :
*

    *
   ***
  *****
 *******
*********

To understand this program, let me change the space with ’^’ . Now you can easily understand it by going through the for loops. If we replace the spaces with ’^’, it will look like :

^^^^^
^^^^*
^^^***
^^*****
^*******
*********

Sample program to print reverse triangle in java :

Printing a reverse triangle looks same as above. Source :

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int size;
        Character c;

        System.out.println("Enter height of the triangle : ");
        size = sc.nextInt();

        System.out.println("Which character you want to use : ");
        c = sc.next().charAt(0);

        int i, j, k;

        for (i = size; i > 0; i--) {
            for (j = size; j > i; j--) {
                System.out.print(" ");
            }
            for (k = 0; k < (i * 2 - 1); k++) {
                System.out.print(c);
            }
            System.out.println();
        }
    }
}

Sample Example :

Enter height of the triangle :
7
Which character you want to use :
$
$$$$$$$$$$$$$
 $$$$$$$$$$$
  $$$$$$$$$
   $$$$$$$
    $$$$$
     $$$
      $

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