Java Program to Print Mirror Lower Star Triangle Pattern

In this article, we will understand how to print mirror lower star triangle pattern. The pattern is formed by using multiple for-loops and print statements.

Below is a demonstration of the same −

Input

Suppose our input is −

Enter the number of rows : 8

Output

The desired output would be −

The mirror lower star triangle pattern :
* * * * * * * *
 * * * * * * *
  * * * * * *
   * * * * *
    * * * *
     * * *
      * *
       *
       *
      * *
     * * *
    * * * *
   * * * * *
  * * * * * *
 * * * * * * *
* * * * * * * *

Algorithm

Step 1 - START
Step 2 - Declare four integer values namely i, j,k and my_input
Step 3 - Read the required values from the user/ define the values
Step 4 - We iterate through two nested 'for' loops to get space between the characters.
Step 5 - After iterating through the innermost loop, we iterate through another 'for' loop. This will help print the required character.
Step 6 - Now, print a newline to get the specific number of characters in the subsequent lines.
Step 7 - Display the result
Step 8 - Stop

Example 1

Here, the input is being entered by the user based on a prompt. You can try this example live in our coding ground tool .

import java.util.Scanner;
public class MirrorTriangle{
   public static void main(String args[]){
      int i, j, k, my_input;
      System.out.println("Required packages have been imported");
      Scanner my_scanner = new Scanner(System.in);
      System.out.println("A reader object has been defined ");
      System.out.print("Enter the number of rows : ");
      my_input = my_scanner.nextInt();
      System.out.println("The Mirror Lower Star Triangle pattern : ");
      for (i = 1; i <= my_input; i++) {
         for (j = 1; j < i; j++) {
            System.out.print(" ");
         }
         for (j = i; j <= my_input; j++) {
            System.out.print("*" + " ");
         }
         System.out.println();
      }
      for (i = my_input - 1; i >= 0; i--) {
         for (j = 0; j < i; j++) {
            System.out.print(" ");
         }
         for (j = i; j <= my_input - 1; j++) {
            System.out.print("*" + " ");
         }
         System.out.println();
      }
   }
}

Output

Required packages have been imported
A reader object has been defined
Enter the number of rows : 8
The Mirror Lower Star Triangle pattern :
* * * * * * * *
 * * * * * * *
  * * * * * *
   * * * * *
    * * * *
     * * *
      * *
       *
       *
      * *
     * * *
    * * * *
   * * * * *
  * * * * * *
 * * * * * * *
* * * * * * * *

Example 2

Here, the integer has been previously defined, and its value is accessed and displayed on the console.

public class MirrorTriangle{
   public static void main(String args[]){
      int i, j, k, my_input;
      my_input = 8;
      System.out.println("The number of rows is defined as " +my_input);
      System.out.println("The mirror lower star triangle pattern : ");
      for (i = 1; i <= my_input; i++) {
         for (j = 1; j < i; j++) {
            System.out.print(" ");
         }
         for (j = i; j <= my_input; j++) {
            System.out.print("*" + " ");
         }
         System.out.println();
      }
      for (i = my_input - 1; i >= 0; i--) {
         for (j = 0; j < i; j++) {
            System.out.print(" ");
         }
         for (j = i; j <= my_input - 1; j++) {
            System.out.print("*" + " ");
         }
         System.out.println();
      }
   }
}

Output

The number of rows is defined as 8
The mirror lower star triangle pattern :
* * * * * * * *
 * * * * * * *
  * * * * * *
   * * * * *
    * * * *
     * * *
      * *
       *
       *
      * *
     * * *
    * * * *
   * * * * *
  * * * * * *
 * * * * * * *
* * * * * * * *