Deleting an array element in C

Question

I wrote the following program to delete an array element entered by the user.

#include 
#include 

void main() {
    int j, i,          


        

Answer 1

Your method with 2 nested for loops is too complicated. You can simple scan the array with an index i and copy all elements different from key with a different index len. The resulting array length is the final value of len.

Here is a modified version:

#include 
#include 

int main(void) {
    int a[100];
    int i, n, key, len;

    clrscr();
    printf("Enter the number of elements: ");
    if (scanf("%d", &n) != 1) {
        printf("invalid input\n");
        return 1;
    }
    if (n < 0 || n > 100) {
        printf("invalid number of elements\n");
        return 1;
    }
    printf("\nEnter the elements:\n");
    for (i = 0; i < n; i++) {
        if (scanf("%d", &a[i]) != 1) {
            printf("invalid input\n");
            return 1;
        }
    }
    printf("\nEnter the element to delete: ");
    if (scanf("%d", &key) != 1) {
        printf("invalid input\n");
        return 1;
    }

    for (i = len = 0; i < n; i++) {
        if (a[i] != key)
           a[len++] = a[i];
    }

    printf("\nThe new array is:\n");
    for (i = 0; i < len; i++)
        printf("%d ", a[i]);
    printf("\n");
    getch();
    return 0;
}

Notes:

• The prototype for main without arguments is int main(void) and it is considered good style to return 0 for success.

• always test the return value of scanf(). This prevents many bugs and undefined behavior for invalid input. It also saves a lot of time looking in the wrong places when input was just invalid.

• avoid naming a variable l as it looks too close to 1 in many fixed pitch fonts.

• always terminate the program output with a newline.