Filling an Array in C with 0

Question

Ive got a problem with this code, im trying to add up array1 with array2.

I enter the numbers for array2 by Command line parameters.

When i enter 10 numbers it is working but when i add less than 10 I get an Memory access error.

My question is now: how do i fill up the missing array fields with the number 0? For example : I enter 9 numbers and the 10th field should be 0.

Add your code in your question body. Don't link us to a picture of your code. — Tony Tannous, Mar 16 '17 at 22:20
Welcome to Stack Overflow, you should post your code instead of images. — Iharob Al Asimi, Mar 16 '17 at 22:21
The problem you have described and the question you ask are seemingly unrelated. The crash does not come from not initiaialising to zero. The problem is you access `argv` values that do not exist and hence accessing invalid memory. Modify your code to check `argc` first before using any of the `argv` values. — kaylum, Mar 16 '17 at 22:25
Possible duplicate: http://stackoverflow.com/q/5508110/315052 — jxh, Mar 16 '17 at 22:34
`int array2[10] = {0}; for(i = 1; i < argc && i <= 10; ++i) array2[i-1] = atoi(argv[i]);` — BLUEPIXY, Mar 16 '17 at 22:42

Miket25 · Answer 1 · 2017-07-12T02:34:04.753

You are not checking how many command line arguments are passed, and when you index into the command line argument array, you will get an out-of-bounds error.

In you addiren function, you should take advantage of the argc that is passed and used that in your for loop limit.

#include <stdio.h>
#include <stdlib.h>

int addiren(int argc, char**argv){
    int array_one[10] = {0,1,1,2,3,5,8,13,21,35};
    int array_two[10] = {0}; //Quick way to set the array to all zeros
    int array_three[10] = {0};

    //Set array_two with your cmd-line args, notice the use of argc
    for(int i = 1; i<argc && i<=10; i++){
        array_two[i-1] = atoi(argv[i]);
    }

    //Add array_one with array_two to array_three
    for(int i = 0; i<10; i++){
        array_three[i] = array_one[i]+array_two[i];
    }

    //Return an int since that's what the function return type requires
    return 0;
}

Hope this helps!

Filling an Array in C with 0

1 Answers1