C program to print 8 star pattern

Write a C program to print 8 star pattern series using loop. How to print 8 star pattern series using for loop in C programming. Logic to print 8 star pattern series of N columns in C program.

Input N: 5

 ***
*   *
*   *
*   *
 ***
*   *
*   *
*   *
 ***

Required knowledge

Basic C programming, If else, Loop

Must have programming knowledge for this program.

Logic to print 8 star pattern

To simply things for beginners I have divided entire logic in three main sub tasks.

• Print a hollow square star pattern with N columns and (N*2) - 1 rows.
• Modify above hollow square pattern logic. Instead of star(*), print space at top and bottom corners and in the center intersection edge.
• Finally modify hollow square logic to print star instead of space for Nth row.

Below is the step by step descriptive logic to print 8 star pattern.

1. Read number of columns to print from user. Store it in some variable say N.
2. Iterate through (N*2)-1 rows. Run an outer loop with structure for(i=1; i<N*2; i++).
3. Iterate through N columns. Run an inner loop with structure for(j=1; j<=N; j++).
4. Inside inner loop first check conditions for corner and center intersection spaces. Print space for
   1st row and 1st or Nth column = if(i==1 && (j==1 || j==N))
   Nth row and 1st or Nth column = if(i==N && (j==1 || j==N))
   N*2-1 row and 1st or Nth column = if(i==N*2-1 && (j==1 || j==N))
   
5. Print stars for
   1st row or 1st column = if(i==1 || j==1)
   Nth row or Nth column = if(i==N || j==N)
   N*2-1th row = if(i==N*2-1)
   
6. Otherwise print spaces if above conditions does not matches.

Program to print 8 star pattern

/**
 * C program to print 8 star pattern series
 */
#include <stdio.h>

int main()
{
    int i, j, size;

    printf("Enter size: ");
    scanf("%d", &size);

    for(i=1; i<size*2; i++)
    {
        for(j=1; j<=size; j++)
        {
            // Condition for corner and center intersection space
            if((i==1 && (j==1 || j==size)) || (i==size && (j==1 || j==size)) || (i==size*2-1 && (j==1 || j==size)))
                printf(" ");
            else if(i==1 || i==size || i==(size*2)-1 || j==1 || j==size)
                printf("*");
            else
                printf(" ");
        }

        printf("\n");
    }

    return 0;
}

Enter size: 6
 ****
*    *
*    *
*    *
*    *
 ****
*    *
*    *
*    *
*    *
 ****

Screenshot

Happy coding ;)