bits and bytes

Interview Question…

I have following code snippets…

Code snippet 1

int arr[1000000];
int main()
{   
	return arr[0];
}

Code snippet 2:

int arr[1000000] = {10};
int main()
{   
	return arr[0];
}

After compilation of the above snippets the output exe differs in size. The second snippet’s executable is much bigger in size than the first snippet’s executable. See screenshot…

Why?