OnTriggerExit with 2D Colliders?

I want to to make a 2D space game (average) and when I shoot, my sprite keeps going continuously up.
I have set a cube surrounding the outside of the game while the “Is Trigger” is selected with this script:

using UnityEngine;
using System.Collections;

public class DestroyCollider : MonoBehaviour
{
void OnTriggerExit(Collider other)
{
Destroy(other.gameObject);
}
}

Shots are still escaping and is spamming my hierarchy!?
(Sorry im new tho Unity answers)

Hi,

instead of using

void OnTriggerExit(Collider other)

use the 2D version, because you are using a sprite.

void OnTriggerExit2D(Collider2D other)

You could also change the 3D cube for the level boundary to a empty gameobject and give this object a BoxCollider2D, because you are using 2D sprites.

A good idea is also to take a look into the following project(if you dont know it already) because it is a example of a 2D space shooter with 3D Objects.