Why does the array print zero in the beginning with the last digit missing?

Question

I am trying to separate digits of a number and print those individual digits. When I do this -:

#include <stdio.h>
#define size 100

int main()
{
    int num, remainder, arr[size], i=0;

    printf("Enter a number : ");
    scanf("%d", &num);

    while(num != 0)
    {
        remainder = num%10;
        arr[i]=remainder;
        i++;
        num /= 10;
    }

    for(int j=i; j>0; j--)
        printf("%d\t", arr[j]);

    printf("\n");

    return 0;
}

It shows -:

Output

I don't know the reason as to why it's happening. Please help me.

Thank You.

Answer 1

This should work:

#include <stdio.h>
#define size 100

int main()
{
    int num, remainder, arr[size], i=0;

    printf("Enter a number : ");
    scanf("%d", &num);

    while(num != 0)
    {
        remainder = num%10;
        arr[i]=remainder;
        i++;
        num /= 10;
    }

    for(int j=i-1; j>=0; j--)
        printf("%d\t", arr[j]);

    printf("\n");

    return 0;
}

I have changed for(int j=i; j>0; j--) with for(int j=i-1; j>=0; j--).

Or use this code, it is faster can also accepted 0 and any int value

#include <stdio.h>

int main()
{
    int num;
    int i = 1000000000;
    int first_index = 0;

    printf("Enter a number : ");
    scanf("%d", &num);

    while (i>1){
   
       if((num%i*10)/i == 0 && first_index == 0){
           i = i/10;
           if(i==1){
               printf("0");
           }
           continue;
       }
       first_index = 1;
       printf("%d ", (num%i*10)/i);
       i = i/10;
    }
}