Question

What will be the value of vec[2], the third element in the vector, after this code executes?

int main()
{
    const int LENGTH = 4;
    int vec [LENGTH];
    vec[0] = 3;
    vec[2] = vec[0];
    vec[0]++;

    return 0;
}

0

1

3

4

Answer 1

3

So, we can see that vec[0] is set to 3 and then vec[2] is set to vec[0]. Since vec[0] has 3 stored, vec[2] becomes 3. Now vec[0] and vec[2] are not pointers, so the copy is a deep copy, i.e only the value is copied and any change to vec[0] will not reflect on vec[2]. vec[0]++ changes vec[0] to 4, but vec[2] remains 3.