Java Program to Print Downward Right Triangle Number Pattern - 2

In this program we print a downward right triangle number pattern in which every row repeats its own row number. The first row prints 5 five times, the next prints 4 four times, and so on down to a single 1.

Like every pattern program, it is built from nested loops: the outer loop picks the row, and the inner loop prints what goes on that row.

1. The Pattern

For 5 rows the program prints:

5 5 5 5 5
4 4 4 4
3 3 3
2 2
1

2. How the Program Works

Here is what each printed line is made of when numberOfRows is 5:

• The outer loop counts row down from numberOfRows to 1, so the longest row comes first.
• The inner loop runs row times and prints the value of row (not column) each time, followed by a space. That is the only difference from Number Pattern - 7, which prints column and so shows 1 2 3 4 5.
• System.out.println() moves to the next line after each row.

3. Java Program

public class Pattern8 {
    public static void main(String[] args) {
        int numberOfRows = 5;

        // outer loop for the rows, counting down
        for (int row = numberOfRows; row >= 1; row--) {
            // inner loop prints the row number, row times
            for (int column = 1; column <= row; column++) {
                System.out.print(row + " ");
            }
            // move to the next line
            System.out.println();
        }
    }
}

5 5 5 5 5
4 4 4 4
3 3 3
2 2
1

4. Print the Pattern for Any Number of Rows

To let the user choose the size of the pattern, read the number of rows with a Scanner. The loops stay the same.

import java.util.Scanner;

public class Pattern8Input {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter the number of rows: ");
        int numberOfRows = scanner.nextInt();
        scanner.close();

        // outer loop for the rows, counting down
        for (int row = numberOfRows; row >= 1; row--) {
            // inner loop prints the row number, row times
            for (int column = 1; column <= row; column++) {
                System.out.print(row + " ");
            }
            // move to the next line
            System.out.println();
        }
    }
}

Enter the number of rows: 6
6 6 6 6 6 6
5 5 5 5 5
4 4 4 4
3 3 3
2 2
1

5. Summary

• The outer loop picks the row; the inner loop prints the numbers for that row.
• Printing row inside the inner loop repeats the row number; printing column would count 1, 2, 3 instead.
• Keep numberOfRows in a variable, so the same program can print the pattern in any size.

Related Programs

• Java Program to Print Downward Right Triangle Number Pattern - 1
• Java Program to Print Downward Right Triangle Number Pattern - 3
• Java Program to Print Left Triangle Number Pattern - 2
• Java Program to Print Downward Left Triangle Number Pattern - 1
• All Java Pattern Programs