Java Program to Print Triangle of Numbers in Reverse Pattern

Write a Java program to print triangle of numbers in reverse pattern using for loop.

package Shapes3;

import java.util.Scanner;

public class TriangleNumRev1 {

	private static Scanner sc;
	
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		
		System.out.print("Enter Triangle of Numbers in Reverse Rows = ");
		int rows = sc.nextInt();
		
		System.out.println("Triangle of Numbers in Reverse Order Pattern");
		
		for (int i = rows; i >= 1; i-- ) 
		{
			for (int j = 1; j < i; j++ ) 
			{
				System.out.print(" ");
			}
			for(int k = i; k <= rows; k++) 
			{
				System.out.print(k + " ");
			}
			System.out.println();
		}
	}
}

This program prints the triangle pattern of numbers in descending order or reverse order using while loop.

package Shapes3;

import java.util.Scanner;

public class TriangleNumRev2 {

	private static Scanner sc;
	
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		
		System.out.print("Enter Triangle of Numbers in Reverse Rows = ");
		int rows = sc.nextInt();
		
		System.out.println("Triangle of Numbers in Reverse Order Pattern");
		int j, k, i = rows;
		
		while(i >= 1 ) 
		{
			j = 1; 
			while(j < i) 
			{
				System.out.print(" ");
				j++;
			}
			
			k = i;
			while(k <= rows) 
			{
				System.out.print(k + " ");
				k++;
			}
			
			System.out.println();
			i--;
		}
	}
}

Enter Triangle of Numbers in Reverse Rows = 9
Triangle of Numbers in Reverse Order Pattern
        9 
       8 9 
      7 8 9 
     6 7 8 9 
    5 6 7 8 9 
   4 5 6 7 8 9 
  3 4 5 6 7 8 9 
 2 3 4 5 6 7 8 9 
1 2 3 4 5 6 7 8 9 

This Java example uses the do while loop to display the reverse order or descending order numbers in triangle pattern.

package Shapes3;

import java.util.Scanner;

public class TriangleNumRev3 {

	private static Scanner sc;
	
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		
		System.out.print("Enter Triangle of Numbers in Reverse Rows = ");
		int rows = sc.nextInt();
		
		System.out.println("Triangle of Numbers in Reverse Order Pattern");
		int j, k, i = rows;
		
		do
		{
			j = 1; 
			do 
			{
				System.out.print(" ");

			} while(j++ < i);
			
			k = i;
			do 
			{
				System.out.print(k + " ");

			} while(++k <= rows);
			
			System.out.println();

		} while(--i >= 1 ) ;
	}
}

Enter Triangle of Numbers in Reverse Rows = 5
Triangle of Numbers in Reverse Order Pattern
     5 
    4 5 
   3 4 5 
  2 3 4 5 
 1 2 3 4 5