Version: 2017.3

Object.operator ==

Switch to Manual
public static bool operator == (Object x, Object y);

Parameters

x The first Object.
y The Object to compare against the first.

Description

Compares two object references to see if they refer to the same object.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour { public Collider target; void OnTriggerEnter(Collider trigger) { if (trigger == target) print("We hit the target trigger"); } }

Get early out if there is no target.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour { public Transform target; void Update() { if (target == null) return; } }

Be careful when comparing with null.

e.g.

GameObject go = new GameObject();
Debug.Log (go == null); // false

Object obj = new Object(); Debug.Log (obj == null); // true

Instatiating a GameObject adds it to the scene so it's completely initialized (!destroyed). Instantiating a simple UnityEngine.Object has no such semantics, so the it stays in the 'destroyed' state which compares true to null.