Did you look at the slides?
If you are using a PC and your DrawingPanel for the game is named gamePanel,
gamePanel.isKeyDown("Left") returns true if the left arrow key was pressed. So
if (gamePanel.isKeyDown("Left") {
xPursuer = xPursuer - 5;
}
would change the x coordinate of the pursuer (if that is your variable's name) 5 smaller so the next time the pursuer is drawn, it would be 5 pixels farther to the left.
It is similar for the other arrow keys.
On a Mac, use four lettered keys for the directions instead. So, if you use a for left
if (gamePanel.isKeyDown("a") {
xPursuer = xPursuer - 5;
}
