Getting rid of duplicate lines of code

I just finished one of MJW's sh'm'up tutorials and by the end I had multiple lines that were duplicates of each other. For example:

1. {


2. removeChild( bullet );


3. bullets.splice( j, 1 );


4. }

While this used to be okay - I just wanted working code! - Now, after these tutorials I'm spoiled. Some would say a better (though very beginner!) programmer. I feel like I need to compact it and clean it up as much as possible.
So I created a public function called removeClip (first it was removeEnemy, then I figured I could use it for the bullets too, and maybe other things later!) and passed it three variables:

instance of the clip I wanted to remove.

the position it was in the array

and, the array name.

Tada!

1. public function removeClip( movieClip:MovieClip, i:int, array:Array ):void


2. {


3.     removeChild( movieClip );


4.     array.splice( i, 1 );


5. }

Then I just went back through AvoiderGame.as and replaced all those lines that removed the bullet / enemy with:
removeClip( enemy, i, army );
or
removeClip( bullet, j, bullets );

Michael, thanks for teaching us how to code.

EDIT: MJW posted a comment on trimming down my code even more that I'd like to share! (Especially in case you don't read the comments...)

He wrote: "I'm not sure if you know this, but all arrays have a method, .indexOf( item ), that returns the index of the item specified (or -1 if the item is not in the array).

So you can write "array.splice( array.indexOf( movieClip ), 1 )", for example. This way you don't have to pass the index of the item through to the function each time!"

I've used his suggestion, and changed my removeClip function to this:

1. public function removeClip( movieClip:MovieClip, array:Array ):void


2. {


3.     removeChild( movieClip );


4.     array.splice( array.indexOf( movieClip ), 1 );


5. }

I guess if you wanted, you could also make a check to make sure it was part of that array before trying to splice, like this:

1. public function removeClip( movieClip:MovieClip, array:Array ):void


2. {


3.     removeChild( movieClip );


4.     if( array.indexOf( movieClip ) != -1  )


5.     {


6.         array.splice( array.indexOf( movieClip ), 1 );


7.     }


8. }

Anyways, it might not seem like a lot at first. You're only slimming it down by one small variable. But that's one less variable for every bullet that leaves the screen, or hits an enemy, plus every enemy that gets hit, or leaves the screen, and in a much bigger game it would really start adding up.

A little more information about it here from Senocular

MJW Avoider Game ep11ch1

Alrighty-- Another challenge! I already wrote below about my fun with isNaN during this challenge. But let me try to document what I did for the challenge itself. Won't be too long...

Staying in the GameOverScreen.as file, I added the following to the constructor. (I called my array bestScoreArray) I wanted to check if the array was undefined or empty, and if so, create it.

1. if( isNaN(sharedObject.data.bestScoreArray) )


2. {


3.     sharedObject.data.bestScoreArray = new Array();


4. }

Then, I figured I'd plug information when the final score was set. So down in the setFinalScre function:

1. else if( scoreValue > sharedObject.data.bestScore )


2. {


3. //  sharedObject.data.bestScore = scoreValue;


4.     sharedObject.data.bestScoreArray = [scoreValue, sharedObject.data.totalGames, "Test"];         


5. }

I'm grabbing three pieces of information and sticking it in an array -- score, total number of games played when that score was reached, and an arbitrary string of text just to test.

Ok, now I need to make sure it's working, so I threw this down below in the same 'setFinalScore' function. It will loop through the array and 'trace' every item to the output window.

1. for (var i:int = 0; i < sharedObject.data.bestScoreArray.length; i++ )


2. {


3.     trace( i, sharedObject.data.bestScoreArray[i] );


4. }

Now run it.

D'oh! Didn't work... why not? Looking back through my code I realized this was wrong:

1. if( isNaN( sharedObject.data.bestScoreArray ) )

Can you spot why? Because we're creating an array... so it's NEVER going to be a "number" (isNaN checks if something is 'not a number')

So, change that to this, and try again:

1. if( sharedObject.data.bestScoreArray == null )


2. {


3.     sharedObject.data.bestScoreArray = new Array();


4. }

Voila! Should work now. If you have any problems, let me know.

What is isNaN()?

So earlier I worked through MJWs Avoider Game Tutorial Chapter 11 and got to the challenges. I was excited! I wanted to save some data to the local computer too! So my first addition was going to be adding how many times the player played my game. Sounds easy enough, it was using the same idea as saving the highest score, right?

Well, I figured GameOverScreen.as was as good a place as any -if not better!- to do this. So I added the following lines:

1. sharedObject.data.totalGames += 1;


2. trace( sharedObject.data.totalGames ); 

But my output didn't read "1" - it said NaN. Whaaaat?
So I threw in an IF statement:

1. if( sharedObject.data.totalGames == null )


2. {


3.     sharedObject.data.totalGames = 0;


4. }

Haha! MJW helped me to learn to code!
...only problem was: It didn't work. My output still read NaN.
Not one to just ask a question and wait for the answer (sorry, I told you to post a comment on MJW's site if you had a question... I'm a hypocrite) I browsed to Google and searched for an answer.

The answer to my problem was isNaN! Here's what I put in my code:

1. if( isNaN(sharedObject.data.totalGames) )


2. {


3.     sharedObject.data.totalGames = 0;


4. }


5. sharedObject.data.totalGames += 1;


6. trace( sharedObject.data.totalGames );     

Now that works! I didn't even have to 'import' anything... though I did search for that because I accidentally put isNan (note the lower case 'n') in my code and got an error.

So there you go... isNaN()

Michael asked for it...

MJW left a comment asking if I was going to post my game anytime soon. So by, umm... popular demand (Hey, 50% of my blogs' commenters asked for it!!) - here it is!

The game gets difficult REALLY quick. But I don't really expect you to play it long. I'm just trying to get the basics down right now.



http://bigfoot-avoidergame.googlecode.com/files/Avoider.swf

Comments, banter, criticism? Close your browser...
Want to lavish praise? Leave it in the comment section!
Kidding... I want to hear it all - leave me a comment if you play. We'll call it "Comment-Ware"

MJW Avoider Game ep8ch1

...That'd be episode 8, challenge 1

So now that he's shown us the magic of adding sound, he wants us to figure out how to create a Mute button on our own... sheesh. :) This was the easiest challenge, so far. But, so that I can solidify this in my own head, and in case you need help, here goes my thought process:

The first step I wanted to complete, had nothing (directly) to do with sound. I wanted Flash to recognize another button was being pressed. Instead of being original, I picked "m" as my mute button... Feel free to pick L, meaning "Let the music stop", or ß (ALT+0223) for "This music was picked for the beta. If you don't like it you can turn it off."

Going back and referencing my old code, I made these additions:

All of them are in the AvoiderGame.as file.

Create a publicly accessible variable (outside contructor)...

1. public var mKeyIsBeingPressed:Boolean;)

Initialize it in the contructor...

1. mKeyIsBeingPressed = false;

Inside the onKeyPress function

1. if( keyboardEvent.keyCode == 77 )


2. {


3.     mKeyIsBeingPressed = true;


4. }

Michael let you figure out the onKeyRelease function, and a student is not above his teacher, so I'll let you figure that out too.... :P

Then in the onTick function, I used a trace() command as a placeholder

1. if( mKeyIsBeingPressed )


2. {


3.     trace( "You're pressing M!!!" );


4. }

Don't forget to "Disable Keyboard Shortcuts"

...and then watch your Output window. When you press m, it should fill up with "You're pressing M!!!" over and over...



Ok, so it's working, I have a stream of useless output to prove it. Now I want it to actually do something useful! I created some new global variables:

1. public var musicPosition:int;


2. public var musicIsMuted:Boolean;

musicPosition is an integer. It's going to be equal to where the music was muted, so that when it's unmuted it'll play from the same spot. I guess that makes it a pause button... so, sue me.
musicIsMuted is straight forward. It's a true/false value of whether the music is muted.

...and then I initialized them, one in the constructor (musicIsMuted), and one in the onTick function

1. musicIsMuted = false;

and

1. if( mKeyIsBeingPressed )


2. {


3.     if( musicIsMuted )


4.     {


5.  


6.     }


7.     else


8.     {


9.         musicPosition = Math.floor(bgmSoundChannel.position);


10.     }


11. }

Ok, ok.... I did a little more then initialize it. I put together the basic if...else structure I was going to use. If the m key is being pressed, then if the music is already muted, do nothing right now, else check the position (in milliseconds) it was muted at, and put that into our variable, as a whole number (that's what Math.floor() does, if you don't remember)

Now, let's flesh it out some. If the music wasn't muted already, what do we want to do? We want to stop the background music from playing, and we want to change our variable (musicIsMuted) which tells us if the music is playing to true.

1. else


2. {


3.     musicPosition = Math.floor(bgmSoundChannel.position);


4.     bgmSoundChannel.stop();


5.     musicIsMuted = true;


6. }

If the player already muted the music, and now wants it to play again (cause they miss those jazzy synth beats!) then we would want it to play from where it stopped (we can do that by passing the play() function an argument), and change the musicIsMuted variable back to false.

1. if( musicIsMuted )


2. {


3.     bgmSoundChannel = backgroundMusic.play( musicPosition );


4.     musicIsMuted = false;


5. }

Now save everything and test your game... Easy, huh?
Oh, wait, you say it keeps rapidly turning off and on? Crud! Well, we can fix that using some tidbits from Michael's sh'm'up tutorial.

Create another global variable:

1. public var ticksSinceMutePressed:int;

Initialize it in the constructor:

1. ticksSinceMutePressed = 0;

and change your function to:

1. if( mKeyIsBeingPressed )


2. {


3.     if( ticksSinceMutePressed > 10 )


4.     {


5.         if( musicIsMuted )


6.         {


7.             bgmSoundChannel = backgroundMusic.play( musicPosition );


8.             musicIsMuted = false;


9.         }


10.         else


11.         {


12.             musicPosition = Math.floor(bgmSoundChannel.position);


13.             bgmSoundChannel.stop();


14.             musicIsMuted = true;


15.         }


16.     ticksSinceMutePressed = 0;


17.     }


18. }


19. ticksSinceMutePressed += 1;

If you haven't read that tutorial already, and can't piece together what I did, head over and check it out. No use in me re-inventing the wheel.

Avoider Game Shmup

That should do it. Now you can hear the 'thump, thump, thump' of the enemys coming on screen without that pesky synth-music playing in the background!

Disappearing Flash Window?

I've had a bizarre problem happen with Flash CS3 twice now since I've been using it. I don't know what causes this but Flash disappears when I "restore" the window (when it's not maximized) It's really bizarre. I mean, I can work with it maximized just fine, but I don't want it to HAVE to be maximized.
I tried:
Right-clicking it's button in the taskbar and selecting "Move", and then using the arrow keys and/or the mouse. Didn't do anything.
Right-clicking it's button in the taskbar and selecting "Size"... Didn't do anything.
I think I tried reinstalling Flash the first time. (I'm in IT - it was like a personal challenge!) - Didn't do anything.
Reset settings in Flash. Doing this caused my preferences to reset, unfortunately it didn't fix my problem. - Didn't do anything useful.
This time I searched online and found the solution on Experts-Exchange.

"I found this config file and renamed it:
C:\Documents and Settings\%username%\Local Settings\Application Data\Macromedia\Flash 8\en\Configuration\panelset.xml

Flash started again and all windows are visible again.  The above file was recreated..."

So I tried the same thing, since I'm using CS3 they changed the name of the file on us, it's now called "workspacelayout.xml" - when I renamed it (to .old) and restarted Flash, I was able to restore my window and it actually showed up!
"Happy! Happy! Joy! Joy! Happy! Happy! Joy! Joy! Happy....."

Trace()

I cannot over. emphasize. my. love. of. the. Trace. Command (ok, maybe I can overemphasize it)

Seriously though, when it comes to debugging my AS3 code, trace() is invaluable!

For example, when trying to create different start buttons for mouse and keyboard controls I was trying to send navigation events, and changing variables, creating variables... sometimes, at first I wasn't sure if the code I implemented worked so I used trace to spit out some information into the 'output' tab. (It's down between 'Properties' and 'Compiler Errors')

Here's how you use it:

1. trace( variableName ); // Outputs the value of that variable


2. trace( "Your Text Here" ); // Outputs 'Your Text Here'


3. trace( "AvoiderGame.as Line 37 xSpeed = ", xSpeed ); //Outputs 'AvoiderGame.as Line 37 xSpeed = 6' (or whatever the value of xSpeed is...)

Easy Peasy Lemon Squeezy!