Wrong C output in terminal

Question

So I was experimenting with arrays in C and came across this weird event where the value of an array changes even though I am not manipulating the data of the elements in that array.

Here is my code:

#include <stdio.h>
#include <conio.h>

int main () {
    int arr[] = {0};

    scanf("%i", &arr[0]);
    scanf("%i", &arr[1]);

    for (int i = 0; i < 2; i++) {
        printf("value of i %i\n", i);
        printf("%i\n", arr[i]);
    }

    getch();
}

and the output was:

2 //this is an input
3 //this is an input
value of i 0
2
value of i 1
1

I have the same code in Turbo C but in Turbo C the value of the elements in that array is correct, the output in Turbo is is:

2 //this is an input
3 //this is an input
value of i 0
2
value of i 1
3

I tried to debug and see when does the change of value happens in the code, so I tried:

#include <stdio.h>
#include <conio.h>

int main () {
    int arr[] = {0};

    scanf("%i", &arr[0]);
    scanf("%i", &arr[1]);

    for (int i = 0; i < 2; i++) {
        printf("value of i %i\n", i);
        printf("%i\n", arr[i]);
    }

    printf("%i\n", arr[0]);
    printf("%i\n", arr[1]);

    getch();
}

and now the output is very weird:

2 //this is an input
3 //this is an input
value of i 0
2
value of i 1
1
2
2

Answer 1

arr[1] is not initialised. Try, int arr[] = {0, 0};