Java Program to Print Backslash Star Pattern

Program to Print Backslash Star Pattern

In this article we are going to see how to print the Backslash star pattern

Example-1

When row values=4
*      
  *    
    *  
      *
Example-2

When column values=5
*        
  *      
    *    
      *  
        *

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Approach:

  • Enter total row and store it an integer variable say row.
  • Take first for loop to print all the rows.
  • Take a inner loop to print the column values.
  • Then go on printing the star symbols according to the iteration.

JAVA Code:

Method-1 : Static Star Character

import java.util.Scanner;
public class Main
{
    public static void main(String[] args) {
    // Take user input for no fo rows 
    System.out.print("Enter the no of rows = ");
    Scanner sc= new Scanner(System.in);
    int r,c,row;
    // store the input value in row
    row=sc.nextInt();
    // loop for no of rows
   for(r=1; r<=row; r++)
   {   
       // inner loop to print symbol
      for(c=1; c<=row; c++)
      {   
          // if row and column have same value print symbol     
         if(r==c)      
            System.out.print("* ");      
         else          
            System.out.print("  ");      
      } 
      System.out.println("");
   } 
    }
}

Output:

Enter the no of rows = 5
*        
  *      
    *    
      *  
        *

Method-2 : User Input Character

import java.util.Scanner;
public class Main
{
    public static void main(String[] args) 
    {
    	 int r,c,row;
    	// Take user input for no fo rows 
    	Scanner sc= new Scanner(System.in);
    	// store the input value in row
    	System.out.print("Enter the no of rows : ");
        row=sc.nextInt();
        // enter random character
    	System.out.print("Enter symbol : ");
    	char s=sc.next().charAt(0);
        // loop for no of rows
        for(r=1; r<=row; r++)
        {   
           // inner loop to print symbol
          for(c=1; c<=row; c++)
          {   
              // if row and column have same value print symbol     
             if(r==c)      
                System.out.print(s+" ");      
             else          
                System.out.print("  ");      
          } 
          System.out.println("");
        } 
    }
}

Output:

Enter the no of rows : 5

Enter symbol : #
#
  #
     #
        #
           #

Explanation:

Let’s understand the program will detailed explanation.

Let we have taken row as 5.

Iteration-I

r=1 (passed through first for loop condition) which will execute till r<=row.

Now inner for loop will execute 1 time and prints a symbol (if column value and row value are same) otherwise a space, which will iterate till c<=row.

*

Iteration-II

r=2 (passed through first for loop condition) which will execute till r<=row.

Now inner for loop will execute 2 time and prints a symbol (if column value and row value are same) otherwise a space, which will iterate till c<=row

 *

Iteration-III

r=3 (passed through first for loop condition) which will execute till r<=row. Now inner for loop will execute 3 time and prints a symbol (if column value and row value are same) otherwise a space, which will iterate till c<=row.

  *

Iteration-IV

r=4 (passed through first for loop condition) which will execute till r<=row. Now inner for loop will execute 4 time and prints a symbol (if column value and row value are same) otherwise a space, which will iterate till c<=row.

   *

Iteration-V

r=5 (passed through first for loop condition) which will execute till r<=row. Now inner for loop will execute 5 time and prints a symbol (if column value and row value are same) otherwise a space, which will iterate till c<=row.

    *

Now r=6 , so first for loop condition fails. Ans no more for loop inside that will be executed. At last we will see a pattern like this as output in the output screen.

*        
 *          
  *          
   *           
    *

C Code:

#include<stdio.h>
int main()
{
   int r,c,k,row;
   printf("Enter the no of rows = ");
   scanf("%d",&row);
   for(r=1; r<=row; r++)
   {    
      for(c=1; c<=row; c++)
      {        
         if(r==c)      
            printf("* ");      
         else          
            printf("  ");      
      }        
      printf("\n");
   }    
   return 0;
}
Output:

Enter the no of rows = 5
*        
  *      
    *    
      *  
        *

C++ Code:

#include <iostream>

using namespace std;

int main()
{
   int r,c,row;
   cout<<"Enter the no of rows = ";
   cin>>row;
   for(r=1; r<=row; r++)
   {    
      for(c=1; c<=row; c++)
      {        
         if(r==c)      
            cout<<("* ");      
         else          
            cout<<("  ");      
      }        
      cout<<("\n");
   }    
   return 0;
}
Output:

Enter the no of rows = 5
*        
  *      
    *    
      *  
        *

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