View source for UnityScript versus JavaScript

=== File name matters ===

UnityScript tries to save you from typing. Most files represent single classes, so automatically, the name of a UnityScript file is used to define a class which the file's contents are assumed to implement.

For instance, the following file Dog.js:

<syntaxhighlight lang="javascript">
function Bark() {
    Debug.Log("Woof!");
}

function Wait() {
    while () {
    }
}

function PlayDead() {
    Application.Quit();
}
</syntaxhighlight>

Is essentially interpreted as the following equivalent C# code:

<syntaxhighlight lang="javascript">
using UnityEngine;

class Dog : MonoBehaviour { // this means Dog derives from MonoBehaviour

    public void Bark() { // These are methods of Dog.  Note that they are automatically public.
        Debug.Log("Woof!");
    }

    public void Wait() {
        while () {
        }
    }

    public void PlayDead() {
        Application.Quit();
    }

}
</syntaxhighlight>

JavaScript just executes code, with no regard to the file the code is stored in.