Thread: sizeof struct

I'm running the following prog :

Code:

#include <iostream>

using namespace std;

struct customer {
    short number;       //   1:
    int postcode;         //   2:
};

int main() {

    cout<<sizeof(customer)<<endl;

}

If I run it with line 1 in comments the output is 4.OK for that.
If I run it with line 2 in comments the output is 2.OK for that too.
But if i run it as it is above the outout is 8.Why is that?

Thank you in advance.