Affect every object in array.

Question

Hello. What I'm trying to do is disable all the lights i have selected in the Inspector, but since the number of lights may vary i can't use: [0], [1], [2] etc. I guess i have to use [Lights.length] but i get the error "Array index is out of range." when i run it maybe cause i haven't set the min of the array. Here is a part of my script if that helps.

 var LightSources : Light[];
 
 function Update ()
 {
 LightSources[LightSources.length].GetComponent.<Light>().enabled = false;
 }

Answer 1

Best Answer

Answer by Cherno · Oct 23, 2015 at 06:26 PM

Loop through the array like this:

 foreach(Light light in LightSources) {
         light.enabled = false;
  }

or

  for(int i = 0; i < LightSources.Length; i++) {
       Light light = LightSources[i];
       light.enabled = false;
 }

As for your error: Note that you try to access the elements at position (LightSources.Length). If LightSources.Length is, say, 5, then you try to access the element. as position 5 However, with a Length of 5, the element positions are 0,1,2,3,4, so 5 is outside the scope of the array. In any way, this would only affect this one element in the array, not all of them as you might have thought.

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Ant0ny · Oct 23, 2015 at 06:57 PM 1

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I'm not sure i need a loop for what i want to do. I just want to disable all the lights that's all. Instead of using LightSources[0].GetComponent.<Light>().enabled = false; i want to use a line that will disable them all at once. Since i can't use LightSources[0, LightSources.length].GetComponent.<Light>().enabled = false; there must be something similar.

Eno-Khaon Ant0ny · Oct 23, 2015 at 07:09 PM 1

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A loop is the means of making changes to multiple objects at once.

@Cherno has it right. You already have your array, so you simply need to change each object in the array.

That said, even if there were a function to modify all elements in an array simultaneously, on the backend, it would still have to go one-by-one, so it would have an identical computational cost.

Edit: Additionally, you can have an array of Lights to populate coinciding with your lightsources. For example:

 private var Light[] lights;

 function Start()
 {
     for(var i = 0; i < LightSources.length; i++)
     {
         lights[i] = LightSources[i].GetComponent(Light);
     }
 }

Then, in your Update() function, you can turn off the "lights" rather than getting the components back out of the "LightSources" every time.

roojerry Ant0ny · Oct 23, 2015 at 07:43 PM 1

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I don't really recommend it, as a simple loop would be more readable and more efficient, but this fits your one line requirement

using System.Linq

 LightSources.ForEach(light => light.enabled = false);

still just a loop on the backend

Ant0ny · Oct 23, 2015 at 08:04 PM 0

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Ahhh, I see now. It's working fine. I though it would be much easier, something to do with length but i guess i was wrong. Cheers guys !

Affect every object in array.

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