Java Program to Print Hollow Left Pascals Star Triangle

Write a Java program to print hollow left pascals star triangle using for loop. 

package ShapePrograms2;

import java.util.Scanner;

public class HollowLeftPascal1 {
	private static Scanner sc;
	
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		
		int i, j, k;
		
		System.out.print("Enter Hollow Left Pascals Triangle Pattern Rows = ");
		int rows = sc.nextInt();
		
		System.out.println("Printing Hollow Left Pascals Triangle Star Pattern");
		
		for (i = 1 ; i <= rows; i++ ) 
		{
			for (j = rows ; j > i; j-- ) 
			{
				System.out.print(" ");
			}
			for(k = 1; k <= i; k++) 
			{
				if(k == 1 || k == i) {
					System.out.print("*");
				}
				else {
					System.out.print(" ");
				}
			}
			System.out.println();
		}
		
		for (i = 1; i <= rows - 1; i++ ) 
		{
			for (j = 1 ; j <= i; j++ ) 
			{
				System.out.print(" ");
			}
			for(k = rows - 1; k >= i; k--) 
			{
				if(k == rows - 1 || k == i) {
					System.out.print("*");
				}
				else {
					System.out.print(" ");
				}
			}
			System.out.println();
		}
	}
}
Java Program to Print Hollow Left Pascals Star Triangle

This Java example prints the stars in a hollow left pascals triangle pattern using a while loop.

package ShapePrograms2;

import java.util.Scanner;

public class HollowLeftPascal2 {
	private static Scanner sc;
	
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		
		System.out.print("Enter Hollow Left Pascals Triangle Pattern Rows = ");
		int rows = sc.nextInt();
		
		System.out.println("Printing Hollow Left Pascals Triangle Star Pattern");
		int i = 1, j, k;
		
		while (i <= rows ) 
		{
			j = rows ;
			while ( j > i) 
			{
				System.out.print(" ");
				j-- ;
			}
			k = 1;
			while( k <= i) 
			{
				if(k == 1 || k == i) {
					System.out.print("*");
				}
				else {
					System.out.print(" ");
				}
				k++;
			}
			System.out.println();
			i++;
		}
		
		i = 1;
		while ( i <= rows - 1 ) 
		{
			j = 1 ;
			while ( j <= i ) 
			{
				System.out.print(" ");
				j++;
			}
			
			k = rows - 1;
			while( k >= i) 
			{
				if(k == rows - 1 || k == i) {
					System.out.print("*");
				}
				else {
					System.out.print(" ");
				}
				k--;
			}
			System.out.println();
			i++;
		}
	}
}
Enter Hollow Left Pascals Triangle Pattern Rows = 8
Printing Hollow Left Pascals Triangle Star Pattern
       *
      **
     * *
    *  *
   *   *
  *    *
 *     *
*      *
 *     *
  *    *
   *   *
    *  *
     * *
      **
       *

Java program to display hollow left pascals star triangle using do while loop.

package ShapePrograms2;

import java.util.Scanner;

public class HollowLeftPascal3 {
	private static Scanner sc;
	
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		
		System.out.print("Enter Hollow Left Pascals Triangle Pattern Rows = ");
		int rows = sc.nextInt();
		
		System.out.println("Printing Hollow Left Pascals Triangle Star Pattern");
		int i = 1, j, k;
		
		do
		{
			j = rows ;
			do 
			{
				System.out.print(" ");

			} while ( j-- > i);
			k = 1;
			do
			{
				if(k == 1 || k == i) {
					System.out.print("*");
				}
				else {
					System.out.print(" ");
				}

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

		} while (++i <= rows );
		
		i = 1;
		do 
		{
			j = 1 ;
			do
			{
				System.out.print(" ");

			} while ( j++ <= i );
			
			k = rows - 1;
			do 
			{
				if(k == rows - 1 || k == i) {
					System.out.print("*");
				}
				else {
					System.out.print(" ");
				}

			} while( --k >= i);
			System.out.println();

		} while ( ++i <= rows - 1 );
	}
}
Enter Hollow Left Pascals Triangle Pattern Rows = 10
Printing Hollow Left Pascals Triangle Star Pattern
          * 
         ** 
        * * 
       *  * 
      *   * 
     *    * 
    *     * 
   *      * 
  *       * 
 *        * 
  *       *
   *      *
    *     *
     *    *
      *   *
       *  *
        * *
         **
          *

About Suresh

Suresh is the founder of TutorialGateway and a freelance software developer. He specialized in Designing and Developing Windows and Web applications. The experience he gained in Programming and BI integration, and reporting tools translates into this blog. You can find him on Facebook or Twitter.