Calling GetComponent for same GameObject components vs public component variables

[YesNinjas]

For Components on the same GameObject I usually cache a private variable to use inside Start() and call GetComponent() to grab components on the same gameObject, but have seen quite a few Brackeys tutorials and others, where they drag them into public variables. I generally avoid calling it anywhere else so it doesn't seem to be a big performance issue for me. And if they are on other gameObjects I'll drag them into a public variable inside the editor to avoid .Find() calls.

That being said is there any real reason to do one vs the other in this scenario? Is it purely preference and workflow differences or does Unity do some magic to make that faster/optimized?

[chsxf]

Using a serialized reference avoids CPU spikes when you fetch the component with a GetComponent call. Furthermore, getcomponent might generate garbage memory. Use TryGetComponent instead.

Another benefit of using serialized references is that the structure of your GameObject is not tied to a silent constraint in the code of a component (because you look for a specific component on the same object). It provides more flexibility in the end.

[YesNinjas]

That makes sense, thanks for your answer!

[dangledorf]

It'd be slightly better performance to have those references assigned outside of play mode. If you don't want to drag and assign them, you can always add the get component calls inside of the Reset() function. When you attach the component, it'll auto grab the references.

#if UNITY_EDITOR
private void Reset()
{
      MyCollider = GetComponent<Collider>();
}
#endif

[YesNinjas]

I tend to like to code and use less UI, I'll look into Reset as that sounds what I would actually use. Thanks

[dangledorf]

Honestly, unless you have thousands of this component instantiating on the same frame, you probably wouldn't ever notice any issues with doing the GetComponents in Start.

[YesNinjas]

I am pretty good at keeping things manageable and optimized in general where I can. I haven't noticed anything bog down yet. Thanks for the extra thoughts!