RaycastHit2D.collider

Description

The collider hit by the ray.

This can be useful if the hit object has more than one collider - this property can be used to determine the specific collider rather than just the object.

Note that some functions that return a single RaycastHit2D will leave the collider as NULL which indicates nothing hit. RaycastHit2D implements an implicit conversion operator converting to bool which checks this property allowing it to be used as a simple condition check for whether a hit occurred or not.

#pragma strict
//Attach this script to an empty gameobject.
//When you click on a sprite with a collider it will tell you it's name.
function Update() {
    //If the left mouse button is clicked.
    if (Input.GetMouseButtonDown(0)) {
        //Get the mouse position on the screen and send a raycast into the game world from that position.
        var worldPoint = Camera.main.ScreenToWorldPoint(Input.mousePosition);
        var hit = Physics2D.Raycast(worldPoint, Vector2.zero);
        //If something was hit, the RaycastHit2D.collider will not be null.
        if (hit.collider != null) {
            Debug.Log(hit.collider.name);
        }
    }
}

using UnityEngine;
using System.Collections;

//Attach this script to an empty gameobject.
//When you click on a sprite with a collider it will tell you it's name.
public class ExampleClass : MonoBehaviour
{
    void Update()
    {
        //If the left mouse button is clicked.
        if (Input.GetMouseButtonDown(0))
        {
            //Get the mouse position on the screen and send a raycast into the game world from that position.
            Vector2 worldPoint = Camera.main.ScreenToWorldPoint(Input.mousePosition);
            RaycastHit2D hit = Physics2D.Raycast(worldPoint, Vector2.zero);

            //If something was hit, the RaycastHit2D.collider will not be null.
            if (hit.collider != null)
            {
                Debug.Log(hit.collider.name);
            }
        }
    }
}