C program to delete element from an array

Write a C program to delete element from array at specified position. How to remove element from array at given position in C programming. Logic to remove element from any given position in array in C program. The program should also print an error message if the delete position is invalid.

Input array elements: 10 20 30 40 50
Input position to delete: 2

Array elements: 10, 30, 40, 50

Required knowledge

Basic Input Output, For loop, Array

Logic to remove element from array

Array is a linear data structure. It provides index based fast mechanism to access its elements. But insertion or deletion from an array is a costly operation.

Literally speaking there isn’t anything such as deleting element from array. In general you copy elements of the array towards left. Suppose I say you need to delete the 2^nd element from given array. You will do it as.

Step by step descriptive logic to remove element from array.

1. Move to the specified location which you want to remove in given array.
2. Copy the next element to the current element of array. Which is you need to perform array[i] = array[i + 1].
3. Repeat above steps till last element of array.
4. Finally decrement the size of array by one.

Program to delete element from array

/*
 * C program to delete an element from array at specified position
 */

#include <stdio.h>
#define MAX_SIZE 100

int main()
{
    int arr[MAX_SIZE];
    int i, size, pos;

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

    /* Input element position to delete */
    printf("Enter the element position to delete : ");
    scanf("%d", &pos);


    /* Invalid delete position */
    if(pos < 0 || pos > size)
    {
        printf("Invalid position! Please enter position between 1 to %d", size);
    }
    else
    {
        /* Copy next element value to current element */
        for(i=pos-1; i<size-1; i++)
        {
            arr[i] = arr[i + 1];
        }

        /* Decrement array size by 1 */
        size--;

        /* Print array after deletion */
        printf("\nElements of array after delete are : ");
        for(i=0; i<size; i++)
        {
            printf("%d\t", arr[i]);
        }
    }

    return 0;
}

Enter size of the array : 5
Enter elements in array : 10 20 30 40 50
Enter the element position to delete : 2

Elements of array after delete are : 10      30      40      50

Happy coding 😉