Confused about using arrays

[aewarnick]

int billy [] = {16, 2, 77, 40, 12071};
int n, result=0;

int main ()
{
for ( n=0 ; n<5 ; n++ )
{
result += billy[n];
}
cout << result;
return 0;
}

result = 12206

I was trying to figure out why in the for loop isn't n<5 instead n<=5 because there are 5 elements in the array.

I am thinking that the computer sees billy[n] as billy[0], billy[1], billy[2] . . .etc. when the loop is done. Am I right?