Save previous Enum variable in Update

Questions & Answers
1

I am trying to create a method that remembers the previous variable value.

I have the following:

    enum Direction { UP, DOWN, LEFT, RIGHT, NONE };
    Direction myDirection;
    Direction previousDirection;

 private void Update()
    {
        if (Input.GetKeyDown(KeyCode.W))
        {
            myDirection = Direction.UP;
        }
        if (Input.GetKeyDown(KeyCode.A))
        {
            myDirection = Direction.LEFT;
        }
        if (Input.GetKeyDown(KeyCode.S))
        {
            myDirection = Direction.DOWN;
        }
        if (Input.GetKeyDown(KeyCode.D))
        {
            myDirection = Direction.RIGHT;
        }

Now I want every time myDirecition changes, the previous state to be remembered in previousDirection

2

Just do:

void SetDirection(Direction aNewDir)
{
    previousDirection = myDirection;
    myDirection = aNewDir;
}

private void Update()
{
    if (Input.GetKeyDown(KeyCode.W))
    {
        SetDirection(Direction.UP);
    }
    if (Input.GetKeyDown(KeyCode.A))
    {
        SetDirection(Direction.LEFT);
    }
    if (Input.GetKeyDown(KeyCode.S))
    {
        SetDirection(Direction.DOWN);
    }
    if (Input.GetKeyDown(KeyCode.D))
    {
        SetDirection(Direction.RIGHT);
    }
}

If you want to prevent the previousDirection to change when the same key is pressed multiple times in a row, just change SetDirection to:

void SetDirection(Direction aNewDir)
{
    if (aNewDir != myDirection)
        previousDirection = myDirection;
    myDirection = aNewDir;
}