Java Program to Print an Inverted Right Triangle Star Pattern

Introduction

Printing various patterns is a common exercise for beginners in programming, helping to understand loops and control structures. In this guide, we will create a Java program to print an inverted right triangle star pattern.

Problem Statement

Create a Java program that:

• Accepts the size of the triangle (number of rows).
• Prints an inverted right triangle using stars (*).

Example:

• Input: size = 5
• Output:

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

Solution Steps

1. Input the Size of the Triangle: The size represents the number of rows in the inverted triangle.
2. Use Nested Loops: Use nested loops to print stars (*) in decreasing order of length.
3. Display the Pattern: Print each row with the correct number of stars, decreasing row by row.

Java Program

// Java Program to Print an Inverted Right Triangle Star Pattern
// Author: [Your Name]

import java.util.Scanner;

public class InvertedRightTriangle {
    public static void main(String[] args) {
        // Step 1: Accept the size of the triangle
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter the size of the inverted right triangle: ");
        int size = sc.nextInt();

        // Step 2: Outer loop for the rows
        for (int i = size; i >= 1; i--) {
            // Step 3: Inner loop to print stars for each row
            for (int j = 1; j <= i; j++) {
                System.out.print("*");
            }
            // Step 4: Move to the next line after each row
            System.out.println();
        }

        // Closing the scanner object
        sc.close();
    }
}

Explanation

Step 1: Input Size

• The program starts by taking input from the user for the size of the triangle using the Scanner object.

Step 2: Outer Loop for Rows

• The outer loop controls the number of rows, starting from the size down to 1. This loop dictates how many stars will be printed in each row.

Step 3: Inner Loop for Stars

• The inner loop prints stars (*) for each row. The number of stars printed corresponds to the current row number, which decreases in each iteration.

Step 4: New Line After Each Row

• After printing each row, the program moves to the next line to begin printing the next row of stars.

Output Example

For size = 5, the output is:

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

For size = 7, the output is:

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

Conclusion

This Java program prints an inverted right triangle using stars (*). The number of stars decreases row by row, creating the inverted shape. This exercise is a useful way to practice working with loops and pattern generation in Java.