Version: 2023.2
Language : English
Call JavaScript functions from Unity C# scripts
Call C/C++/C# functions from Unity C# scripts

Call Unity C# script functions from JavaScript

You might want to call some Unity code from your JavaScript plug-inA set of code created outside of Unity that creates functionality in Unity. There are two kinds of plug-ins you can use in Unity: Managed plug-ins (managed .NET assemblies created with tools like Visual Studio) and Native plug-ins (platform-specific native code libraries). More info
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or browser code. For example, you might want a JavaScript UI(User Interface) Allows a user to interact with your application. Unity currently supports three UI systems. More info
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element that triggers a Unity behaviour and needs access to that method.

The recommended way to send data or notifications to the Unity C# script from the browser’s JavaScript is to use the SendMessage function to call methods on GameObjectsThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info
See in Glossary
in your Unity project.

Use the SendMessage helper function

Use SendMessage to call a Unity method of the Unity scripting API from JavaScript code.

There are some restrictions for what sort of methods you can pass. You can only call methods of a GameObject, not general C# methods attached to other objects. Also, only use SendMessage to call a method if one of the following is true:

  • The method takes no parameters.
  • The method has one parameter and that parameter is a single string.
  • The method has one parameter and that parameter is a single number.

Methods with more than one parameter or with parameters of other types can’t be called using SendMessage.

Example SendMessage code

To make the call from a JavaScript plug-in embedded in your project, use the following code:

MyGameInstance.SendMessage(objectName, methodName, value);
  • objectName is the name of an object in your sceneA Scene contains the environments and menus of your game. Think of each unique Scene file as a unique level. In each Scene, you place your environments, obstacles, and decorations, essentially designing and building your game in pieces. More info
    See in Glossary
    .
  • methodName is the name of a method in the script, currently attached to that object.
  • value can be a string, a number, or can be empty.

The following code is a further example that shows each of the types of methods that you can call with different parameters.

MyGameInstance.SendMessage('MyGameObject', 'MyFunction');
MyGameInstance.SendMessage('MyGameObject', 'MyFunction', 5);
MyGameInstance.SendMessage('MyGameObject', 'MyFunction', 'MyString');

To make a call from the global scope of the embedding page, refer to Call JavaScript functions from global scope.

Additional resources

Call JavaScript functions from Unity C# scripts
Call C/C++/C# functions from Unity C# scripts