Flash Function made Easy 3

by AB1

ActionScript Code

Explanations

var xBox:Number = 200;

var yBox:Number = 200;

function locateBox()

{

Box._x = xBox;

 Box._y = yBox

}

function moveBoxWithKeys()

{

 if (Key.isDown(Key.RIGHT)) 

{xBox = xBox+10;

  yBox = yBox;}

 if (Key.isDown(Key.LEFT))

 {xBox = xBox-10;

  yBox = yBox;}

if (Key.isDown(Key.UP))

{xBox = xBox;

yBox = yBox-10;}

if (Key.isDown(Key.DOWN))

{xBox = xBox;

yBox = yBox+10;}

}

this.onEnterFrame = function()

{

locateBox();

moveBoxWithKeys();

}

The first two lines place our box in the center of the stage (400x400).

Then there is a function called locateBox(); now, you should be able to say what this function does: it just stores the box x coordinate (Box._x) in the variable xBox and the box y coordinate (Box._y) in the yBox variable. You understand why I called it locateBox!

Then follows a (long) function called moveBoxWithKeys ; no need to tell you what it does! This function combines 4 actions(the four if):

1-If the RIGHT key is down, the x coordinate is increased of 10 pixels (the y coordinate stays the same).

2-If the LEFT key is down, the x coordinate is decreased of 10 (the y coordinate stays the same).

 3-If the UP key is down, the y coordinate is decreased (don’t forget: the y axis is oriented from Top to Bottom); the x stays the same.

4-If the DOWN key is down, the y coordinate is increased and the x stays the same.

Finally, the last function makes work the first two functions (it’s a lazy one!): every time we enter a frame, Flash locates the box with the function locateBox  and moves it with the function moveBoxWithKeys.