Using System.Collections.Generic;

Archived Forums Questions & Answers
1

Just a curious question.

using UnityEngine;

using System.Collections;

using System.Collections.Generic;

This is what I often show from scripts that have lists. Why do we need System.Collections when we have System.Collections.Generic?

2 Answers

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2

Because Systems.Collections contains IEnumerator, which you use for coroutines.

Of course, if you're not using coroutines in a particular script, then there's no reason to import System.Collections that I can think of. It doesn't hurt anything to have it there just in case, though.

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And I suppose to be totally obvious we should mention that Systems.Collections.Generic does not contain IEnumerator.

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3

This may not be super obvious, but including Systems.Collections does not automatically include Systems.Collections.Generic

You could do

Systems.Collections.Generic.List<myClass> myList;

But that’s a lot of unneeded typing every time you make a list.

You actually cannot do the former. Unity is refusing to compile when I did it a few minutes ago.

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Yes, but the question was "if I'm importing System.Collections.Generic, what's the point of importing System.Collections?"

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Thanks @Bluntweapon. I had no idea if it would work or not. Will remove it from my answer.

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