Unity Fundamentals — Coroutines

So you want more control or customisation of your events occurring in every frame provided by the Update function. If this is the case, let me introduce you to Coroutines.

A Coroutine is like a function that can pause execution and return control to Unity until a condition or action takes place for it to continue. Consider it to be a routine that you want to carry out.

In Unity, we specify a Coroutine as a IEnumerator.

IEnumerator CoroutineName()
  {
     // Your Code
  }

By default, a Coroutine is resumed on the frame after it yields, but it is possible to introduce a time delay using a Yield command. Accompanied by a WaitForSeconds, the yield command can pause the Coroutine for however long you specify.

IEnumerator CoroutineName()
  {
     Actions to be performed;
     yield return new WaitForSeconds(5.0f); // 5 seconds
  }

Lets, take a real example. We want to spawn an enemy every five seconds in a random X location between -2.3f and 2.3f.

In the above example of a SpawnManager; We use an infinite loop to create the enemy every 5 seconds within the IEnumerator and Yield. You will notice that we started the IEnumerator within the Start function.

Danger — Infinite loops should be used with caution as if not appropriately controlled; they can crash your game or computer.

I hope this article has helped you with Coroutines and IEnumerators. Check out my other articles on Unity Fundamentals.