JavaScript array.push() doesn't seem to work

Question

So, I'm trying to make an array for enemies in my small game, but Unity doesn't like array.push().

Here's the code:

 #pragma strict
 
 var Health : float = 100;
 var positionX : int;
 var positionY : int = 1;
 var positionZ : int;
 var enemyArray = [];
 var enemyArrayLength : int = 10;
 
 function Update()
 {
     //Destroy(gameObject);
     for(var i : int = 0; i < enemyArrayLength; i++){
     enemyArray.push(enemyCreate());
     Debug.Log("i spawn an enemy");
     }    
 }
 
 function ApplyDamage (PlayerDamage : int)
 {
     Health -= PlayerDamage;
     
     if(Health <= 0)
     {
         Destroy(gameObject);
         //enemyArray.pop();
     }
 }
 
 function enemyCreate() 
 {
     coordMaker();
     var enemy = Instantiate(gameObject, Vector3(positionX, positionY, positionZ), transform.rotation);
 }
 
 function coordMaker()
 {
     var random : int = (Random.Range(1,3));
     if(random==1)
     {
     positionX = transform.position.x + Random.Range(1, 6);
     positionY = transform.position.y;
     positionZ = transform.position.z + Random.Range(1, 6);
     Health = 100;
     }
     else
     {
     positionX = transform.position.x - Random.Range(1, 6);
     positionY = transform.position.y;
     positionZ = transform.position.z - Random.Range(1, 6);
     Health = 100;
     }    
 }

Please help, guys, I don't know who to ask!

Answer 1

Best Answer

Answer by Baste · Feb 25, 2015 at 11:07 AM

You're using a built in array when you're doing this:

 var enemyArray = [];

Those are .NET arrays, and can't be resized, so they lack the .push method. Replace it with a "JavaScript Array":

 var enemyArray = new Array();

You also need to actually return an object from the enemyCreate method, otherwise things will go poorly:

 function enemyCreate() 
 {
     coordMaker();
     var enemy = Instantiate(gameObject, Vector3(positionX, positionY, positionZ), transform.rotation);
     return enemy;
 }

I'd suggest reading up on the two different array types here. Remember, Unity's "JavaScript" is NOT JavaScript. It's C# dressed up to look like JavaScript.

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Hoeloe · Feb 25, 2015 at 11:20 AM 1

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It's not "C# dressed up to look like JavaScript", it's a variation of JavaScript called UnityScript, which is adapted to fit the Unity API.

Also, I recommend not using "Array", but using Lists ins$$anonymous$$d. They're much more reliable. http://unity3d.com/learn/tutorials/modules/intermediate/scripting/lists-and-dictionaries

In general, if you need a collection of objects that doesn't change size, use a built-in array (that's using [] notation). If you need a collection of objects that can change size freely, use Lists. You should never use Unity's "Array" class, it's bad program$$anonymous$$g practice.

SamTheT · Feb 25, 2015 at 12:05 PM 0

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Baste, your method worked, enemies spawn, but AI doesn't to them, so they are just standing there, even though I'm near, but when I didn't use the array, they all with AI. Any suggestions? I'm noob with arrays :(

JavaScript array.push() doesn't seem to work

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