6. Keeping Scopes Small

Data abstraction and hiding closely relates to the scopes of variables and operations.

In view of good design we must pursue the goal of localizing attributes and behaviors as much as possible.

This greatly improves debugging, testing, documentation, and extensibility of the entire system.

Keeping minimal scopes emphasizes good programming style.

Consider:

    int temp;
    void swap( int* pleft, int* pright )
    {
        temp = *pleft;
        *pleft = *pright;
        *pright = temp;
    }

Better:

    void swap( int* pleft, int* pright )
    {
        int temp = *pleft;
        *pleft = *pright;
        *pright = temp;
    }