Program to Print Hollow Square Star Pattern
In this article we are going to see how to print the hollow square star program.
Example-1 When row value=4 * * * * * * * * * * * *
Example-2: When row value=5 * * * * * * * * * * * * * * * *
Now, let’s see the actual program to print it.
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Approach:
- Enter total row and store it in an integer variable
row. - Take first for loop to print all rows.
- Take second/inner for loop to print column values.
- Then go on printing the star symbols according to the iteration condition i.e.
if(r == 1 || r == row || c == 1 || c == row) .
JAVA Code:
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++)
{
// printing stars by checking condition
for(c = 1; c <= row; c++)
if(r == 1 || r == row || c == 1 || c == row)
System.out.print("* ");
else
System.out.print(" ");
System.out.print("\n");
}
}
}
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 sym= s.next().charAt(0);
//for loop for rows
for(r = 1; r <= row ; r++)
{
// printing stars by checking condition
for(c = 1; c <= row; c++)
if(r == 1 || r == row || c == 1 || c == row)
System.out.print(sym+" ");
else
System.out.print(" ");
System.out.print("\n");
}
}
}
Output: Enter rows : 5 Enter character : # # # # # # # # # # # # # # # # #
Explanation :
Let’s understand the program by going through the detailed explanation.
We have taken row value as 5.
Iteration-1
r=1 (passes the first for loop condition) because it will execute until r<= row.
second for loop will iterate up to 1 to row time and for each iteration it will check the condition if(r == 1 || r == row || c == 1 || c == row) for each if condition satisfy it will print * and for each if condition fails it will print space so star will print 5 time .
* * * * *
Iteration-2
r=2 (passes the first for loop condition) because it will execute until r<= row.
second for loop will iterate up to 1 to row time and for each iteration it will check the condition if(r == 1 || r == row || c == 1 || c == row) for each if condition satisfy it will print * and for each if condition fails it will print space so star will print 2 time .
* *
Iteration-3
r=3 (passes the first for loop condition) because it will execute until r<= row.
second for loop will iterate up to 1 to row time and for each iteration it will check the condition if(r == 1 || r == row || c == 1 || c == row) for each if condition satisfy it will print * and for each if condition fails it will print space so star will print 2 time .
* *
Iteration-4
r=4 (passes the first for loop condition) because it will execute until r<= row.
second for loop will iterate up to 1 to row time and for each iteration it will check the condition if(r == 1 || r == row || c == 1 || c == row) for each if condition satisfy it will print * and for each if condition fails it will print space so star will print 2 time .
* *
Iteration-5
r=5 (passes the first for loop condition) because it will execute until r<= row.
second for loop will iterate up to 1 to row time and for each iteration it will check the condition if(r == 1 || r == row || c == 1 || c == row) for each if condition satisfy it will print * and for each if condition fails it will print space so star will print 5 time .
* * * * *
Now r=6, so first for loop condition will fail. So next for loop will not be executed any more.
Now, after end of all iteration we will see the complete pattern is printed on the output screen like this
* * * * * * * * * * * * * * * *
C Code:
#include <stdio.h>
int main() {
int r, row, c ,d;
printf("Enter rows: ");
scanf("%d", &row);
for(r = 1; r <= row ; r++)
{
for(c = 1; c <= row; c++)
if(r == 1 || r == row || c == 1 || c == row)
printf("* ");
else
printf(" ");
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++)
{
for(c = 1; c <= row; c++)
if(r == 1 || r == row || c == 1 || c == row)
cout << "* ";
else
cout << " ";
cout <<"\n";
}
return 0;
}
Output: Enter rows : 5 * * * * * * * * * * * * * * * *
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