Java Program to Print Hollow Tringle Star Pattern

In this article we are going to see how to print the hollow triangle star program.

Example-1

When row value=4
     *
   *  *
  *    *
*******

Example-2:

When row value=5
      *
    *  *
   *     *
  *       *
*********

Now, let’s see the actual program printing it.

Interested in programming and want to excel in it by choosing the short ways. Then, practicing with the available Java Program list is mandatory.

Approach:

Enter total row and store it in an integer variable row.
Take first for loop to print all rows.
Take first inner for loop to print column values i.e., first inner for loop will print all the spaces in the column.
Take second inner for loop to print column values i.e., shaping the tringle with spaces.
Take third inner for loop to print stars according to condition , i.e. if(r==row || (c==1 || c==2*r-1)) .
Then go on printing the star symbol according to loop.

JAVA Code:

Static Star Character
User Input Character

Method-1 : Static Star Character

import java.util.*;
public class Main 
{    
    public static void main(String args[])   
    {   // taking variable for loop iteration and row .
    int row,r,c,d;
    //creating object 
    Scanner s = new Scanner(System.in);
    // entering the number of row
    System.out.print("Enter rows : ");
    row = s.nextInt();
    //for loop for rows
    for(  r=1; r<=row; r++)
    {//Print each row 
        for(  c=r; c<row; c++)
        //Printing space for tringle shape 
            System.out.print(" "); 
        for(  c=1; c<2*r; c++)
        {
            //printing stars
            if(r==row || (c==1 || c==2*r-1))
                System.out.print("*"); 
            else 
                System.out.print(" "); 
      }
      //moving to next line
        System.out.println(""); 
    }
       
    }
}

Output:

Enter rows : 5
       *
     *  *
   *     *
  *       *
*********

Method-2 : User Input Character

import java.util.*;
public class Main 
{    
    public static void main(String args[])   
    {   // taking variable for loop iteration and row .
    int row,r,c,d;
    //creating object 
    Scanner s = new Scanner(System.in);
    // entering the number of row
    System.out.print("Enter rows : ");
    row = s.nextInt();
    // Entering any Character
    System.out.print("Enter character : ");
    char ch= s.next().charAt(0);
    //for loop for rows
    for(  r=1; r<=row; r++)
    {//Print each row 
        for(  c=r; c<row; c++)
        //Printing space for tringle shape 
            System.out.print(" "); 
        for(  c=1; c<2*r; c++)
        {
            //printing stars
            if(r==row || (c==1 || c==2*r-1))
                System.out.print(ch); 
            else 
                System.out.print(" "); 
      }
      //moving to next line
        System.out.println(""); 
    }
       
    }
}

Output:

Enter rows : 5
Enter character : *
       *
     *  *
   *     *
  *       *
*********

C Code:

#include <stdio.h>
int main() {
   int r, row, c ,d;
   printf("Enter rows: ");
   scanf("%d", &row);
      for(  r=1; r<=row; r++)
    {//Print each row 
        for(  c=r; c<row; c++)
        //Printing space for tringle shape 
            printf(" "); 
        for(  c=1; c<2*r; c++)
        {
            //printing stars
            if(r==row || (c==1 || c==2*r-1))
                printf("*"); 
            else 
               printf(" "); 
      }
      //moving to next line
       printf("\n"); 
    }
   return 0;
}

Output:

Enter rows : 5
       *
     *  *
   *     *
  *       *
*********

C++ Code:

#include <iostream>
using namespace std;
int main()
{
   int row, r , c ,d ;
   cout << "Enter  rows: ";
   cin >> row;
  for(  r=1; r<=row; r++)
    {//Print each row 
        for(  c=r; c<row; c++)
        //Printing space for tringle shape 
            cout << " "; 
        for(  c=1; c<2*r; c++)
        {
            //printing stars
            if(r==row || (c==1 || c==2*r-1))
               cout <<"*"; 
            else 
               cout << " "; 
      }
      //moving to next line
       cout << "\n"; 
    }
   return 0;
}

Output:

Enter rows : 5
       *
     *  *
   *     *
  *       *
*********

Related Java Star Pattern Programs: