C program to copy one array to another using pointers

Write a C program to copy one array elements to another array using pointers. How to copy array elements from one array to another array using pointers. Logic to copy one array to another array using pointers in C programming.

Input array1 elements: 10 -1 100 90 87 0 15 10 20 30

Array1: 10 -1 100 90 87 0 15 10 20 30
Array2: 10 -1 100 90 87 0 15 10 20 30

Required knowledge

Basic C programming, Array, Pointers, Array and Pointers

Logic to copy one array to another array using pointers

Step by step descriptive logic to copy one array to another using pointers.

1. Input size and elements in first array, store it in some variable say size and source_array.
2. Declare another array say dest_array to store copy of source_array.
3. Declare a pointer to source_array say *source_ptr = source_array and one more pointer to dest_array say *dest_ptr = dest_array.
4. Copy elements from source_ptr to desc_ptr using *desc_ptr = *source_ptr.
5. Increment pointers source_ptr and desc_ptr by 1.
6. Repeat step 3 and 4 till source_ptr exists in source_arr memory range.

Program to copy one array to another using pointers

/**
 * C program to copy an array to another array using pointers
 */

#include <stdio.h>

#define MAX_SIZE 100 // Maximum array size


/* Function declaration to print array */
void printArray(int arr[], int size);


int main()
{
    int source_arr[MAX_SIZE], dest_arr[MAX_SIZE];
    int size, i;

    int *source_ptr = source_arr;   // Pointer to source_arr
    int *dest_ptr   = dest_arr;     // Pointer to dest_arr

    int *end_ptr;


    /*
     * Input size and elements in source array
     */
    printf("Enter size of array: ");
    scanf("%d", &size);
    printf("Enter elements in array: ");
    for (i = 0; i < size; i++)
    {
        scanf("%d", (source_ptr + i));
    }


    // Pointer to last element of source_arr
    end_ptr = &source_arr[size - 1];


    /* Print source and destination array before copying */
    printf("\nSource array before copying: ");
    printArray(source_arr, size);

    printf("\nDestination array before copying: ");
    printArray(dest_arr, size);



    /*
     * Run loop till source_ptr exists in source_arr
     * memory range.
     */
    while(source_ptr <= end_ptr)
    {
        *dest_ptr = *source_ptr;

        // Increment source_ptr and dest_ptr
        source_ptr++;
        dest_ptr++;
    }


    /* Print source and destination array after copying */
    printf("\n\nSource array after copying: ");
    printArray(source_arr, size);

    printf("\nDestination array after copying: ");
    printArray(dest_arr, size);


    return 0;
}


/**
 * Function to print array elements.
 * 
 * @arr     Integer array to print.
 * @size    Size of array.
 */
void printArray(int *arr, int size)
{
    int i;

    for (i = 0; i < size; i++)
    {
        printf("%d, ", *(arr + i));
    }
}

Note: You can also write the above while loop as

while(source_ptr <= end_ptr)
    *(dest_ptr++) = *(source_ptr++);

Enter size of array: 10
Enter elements in array: 10 -1 100 90 87 0 15 10 20 30

Source array before copying: 10, -1, 100, 90, 87, 0, 15, 10, 20, 30,
Destination array before copying: 0, 0, 127, 127, 0, 1, 0, 16777472, 0, 0,

Source array after copying: 10, -1, 100, 90, 87, 0, 15, 10, 20, 30,
Destination array after copying: 10, -1, 100, 90, 87, 0, 15, 10, 20, 0,