How to destroy a Gameobject in Unity.

Destroying gameobjects comes in handy in lot of game scenarios. Be it ammo collection or killing an enemy, destroying the object from the scene hierarchy is a must learn skill in Unity. In this tutorial, we will see how to destroy a gameobject in your scene and other efficient ways to avoid garbage built-up.

We will also go through the syntax for using the destroy method for different scenarios. To test the below code, create a new scene, add the default Unity cube or an empty game object and add a new script to it. 

Destroying a gameobject in Unity

You can destroy any object or component using the Destroy function in Unity. Destroy function takes two inputs. First input is the gameobject to be destroyed and the second is the time delay in float. The second argument is not mandatory for the actual object destruction.

Default syntax

Destroy(gameObject,timedelay);

Destroy any gameobject

Destroy(myobj);
//Give the name of your gameobject that you want to destroy in place of myobj

Destroy the Gameobject to which the script is attached

Destroy(this.gameObject);

Destroy Gameobject with a tag

GameObject.Find is very performance expensive. Avoid it inside the void Update function.

Destroy(GameObject.FindWithTag("tag"));

Destroy the Script in which the code is present

The following code will only destroy the script and not the gameobject.

Destroy(this);

Destroy any component attached to the gameobject

Destroy(GetComponent<Animator>());
//removes the animator component from the gameobject

You can use this line of code to destroy any component in Unity like Collider components, rigid body 

Delay destruction of an object

Destroy(this.gameObject,10)
//destroys the gameobject after 10 seconds

Destroy Objects Immediately

The Destroy functions in Unity has a small delay but are generally executed within the same frame. Unity strongly recommends not to use Destroy immediate in games. You can destroy assets using Destroy immediate

DestroyImmediate(this.gameObject);

Destroy Parent Objects

Destroy(transform.parent.gameObject);

The above code will destroy the parent game object. Use it with caution as this will also destroy the other children gameobject sharing the common parent.

Important things to know about destroying gameobjects in Unity

1. Do not execute code in the same script after destroying the gameobject. This is a common mistake done by beginners. Once the script or game object is destroyed, none of the code inside the script will be executed.
2. Destroy(this), destroys only the script not the gameobject.
3. Destroying objects create a lot of garbage that effects performance.
4. Using the destroy method in the void Start function will destroy the object immediately. But this can be used to destroy duplicate script instance when using DonDestroyOnLoad

Efficient way to remove object from scene

To reduce the dump created by destroying objects you can simply set the object as inactive. This way you need not instantiate a prefab when needed, you can just set the gameobject to active. You need not worry if you are destroying one or two gameobjects in a scene. The problem comes when you need to instantiate and destroy large number of objects like bullets in an FPS game.

Video Tutorial