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1
Question by dyangca · Jun 05, 2018 at 05:47 PM · getcomponent

More efficient way to check if GetComponent is null before the actual GetComponent Call?

I've been using this syntax to avoid a null reference exception in the case there's no component found on the gameobject, but it doesn't seem like the best way:


if (GetComponent<GameManager>() != null) { GameManager GM = GetComponent<GameManager>(); }


  • Does this if statement actually perform 2 getcomponent calls?

  • If so, is there a more efficient way ?


thanks

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Answer by Hellium · Jun 05, 2018 at 06:18 PM

Yes, 2 calls to GetComponent are performed

Here is a more efficient way:

 GameManager gameManager = GetComponent<GameManager>();
 if( gameManager != null )
 {
     // Do something with gameManager
 }

Or more compact solution:

 if (TryGetComponent(out GameManager gameManager))
 {
     // Do something with gameManager
 }


But an even more efficient way is to cache the component in the Awake function if possible, in order to reuse it in other functions.

 private GameManager gameManager ;

 void Awake()
 {
     gameManager = GetComponent<GameManager>();
 }

 void Update()
 {
     if( gameManager != null )
     {
         // Do something with gameManager
     }
 }


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avatar image dyangca · Jun 05, 2018 at 06:25 PM 0
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@Hellium Thank you, this is what I was looking for.

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-1

Answer by atulvi · Dec 16, 2020 at 11:02 AM

==> Any Instance Create

 public class GameManager : MonoBehaviour
 { 
 
 private static GameManager instance = null;
         public static GameManager Instance
         {
             get
                 {
                     if(instance == null)
                     {
                         var gameManager = FindObjectsOfType<GameManager>();
                         if(gameManager.Length > 0)
                         {
                             instance = gameManager[0];
                         }
                         else
                         {
                             Debug.LogError("No instance of GameManager exists in the scene.");
                         }
                     }
                     return instance;
                 }
         }
 }
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avatar image Hellium · Dec 16, 2020 at 11:09 AM 0
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I don't see how this answers the question

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