The if statements

In Listing 4, if none of the arrow keys is pressed:

The position coordinates for the text remain unchanged.

This causes the text to be drawn in the same location the next time it is drawn.

If one (or more) of the arrow keys is pressed:

One of the position coordinates is incremented or decremented by a value of one pixel.

This causes the text to be drawn in a different location the next time it is drawn.