koobas.hobune.stream
Is calling GetComponent multiple times bad?
Is calling GetComponent multiple times bad? Or should I cache it?
For example, let's say I need to access multiple variables of the same component
gameObject.GetComponent<ScriptA>().var1 = 534;
gameObject.GetComponent<ScriptA>().var2 = 3534;
gameObject.GetComponent<ScriptA>().var3 = 456;
gameObject.GetComponent<ScriptA>().var4 = 65;
gameObject.GetComponent<ScriptA>().var5 = 874;
Or should I cache it
ScriptA scriptA = gameObject.GetComponent<ScriptA>();
scriptA.var1 = 534;
scriptA.var2 = 3534;
scriptA.var3 = 456;
scriptA.var4 = 65;
scriptA.var5 = 874;
Is there any performance difference between the two? Dose one generate more garbage than the other?
Yes, you should cache it, GetComponent is expensive, that's all. Practically you want caching everything.
As far as I know, there should be no garbage created when you call GetComponent, because you'd just be calling a method of the GameObject class, not creating and destroying an object, which is what would create garbage.
However, performance would be affected, because whenever you call a method, you create overhead, and that's what you want to avoid.
Therefore, when you call gameObject.GetComponent<ScriptA>() five times, instead of once and caching it, you'd be creating 5 times the overhead. Although this may, or may not be noticeable degradation in the performance of the game, it would be good practice to avoid these extra calls, especially when they would be made frequently, e.g. inside Update().
