RequireComponent

class in UnityEngine

Description

The RequireComponent attribute automatically adds required components as dependencies.

When you add a script which uses RequireComponent to a GameObject, the required component will automatically be added to the GameObject. This is useful to avoid setup errors. For example a script might require that a Rigidbody is always added to the same GameObject. Using RequireComponent this will be done automatically, thus you can never get the setup wrong. Note that RequireComponent only checks for missing dependencies during the moment the component is added to a GameObject. Existing instances of the component whose GameObject lacks the new dependencies will not have those dependencies automatically added.

// PlayerScript requires the GameObject to have Rigidbody component
@script RequireComponent(Rigidbody)

var rb: Rigidbody;

function Start() {
    rb = GetComponent.<Rigidbody>();
}


function FixedUpdate() {
    rb.AddForce(Vector3.up);
}

using UnityEngine;

// PlayerScript requires the GameObject to have a Rigidbody component
[RequireComponent(typeof(Rigidbody))]
public class PlayerScript : MonoBehaviour
{
    Rigidbody rb;

    void Start()
    {
        rb = GetComponent<Rigidbody>();
    }

    void FixedUpdate()
    {
        rb.AddForce(Vector3.up);
    }
}