Pass Pointers to Functions in C

In this article, we will show you, How to write a C Program to pass Pointers to Functions. Or How to Pointers to Functions in C programming with a practical example.

TIP: Suggest you refer, Call By Value and Call by Reference and Pointers article to understand the function arguments, and pointers.

Pass Pointers to Functions in C Example 1

Like any other variable, you can pass the pointer as a function argument.

In this program, we created a function that accepts two integer variable and swaps those two variables. I suggest you refer, C Program to Swap two numbers article to understand the logic.

/* Pass Pointers to Functions in C Example  */

#include<stdio.h>
 
void Swap(int *x, int *y)
{
    int Temp;
    Temp = *x;
    *x = *y;
    *y = Temp;
}

int main()
{
    int a, b;
    
    printf ("Please Enter 2 Integer Values :  ");
    scanf("%d %d", &a, &b);
    
    printf("\nBefore Swapping  A = %d and B = %d", a, b);
    
    Swap(&a, &b);
    
    printf(" \nAfter Swapping   A = %d and B = %d \n", a, b);
}

OUTPUT

Pass Pointers to Functions in C Example 2

In this program, we created a function that accepts the array pointer and its size. I suggest you refer C program to find Sum of All Elements in an Array article to understand the function logic.

Within the main program, we used for loop to iterate the array and pass user given element to an array. Next, we are passing an array to a function

/* Pass Pointers to Functions in C Example  */

#include<stdio.h>
 
int SumofArrNumbers(int *arr, int Size)
{
    int sum = 0;
    for(int i = 0; i < Size; i++)
    {
        sum = sum + arr[i];
    }
    return sum;
}
int main()
{
    int i, Addition, Size, a[10];
    printf("Please Enter the Size of an Array : ");
    scanf("%d", &Size);
    
    printf("\nPlease Enter Array Elements  :  ");
    for(i = 0; i < Size; i++)
    {
        scanf("%d", &a[i]);
    }
    
    Addition = SumofArrNumbers(a, Size);
    printf("Sum of Elements in this Array = %d \n", Addition);
    return 0;
}

OUTPUT