Code examples: Call JavaScript and C/C++/C# functions in Unity
Code examples that show interactions between Unity, JavaScript, and C-based code.
Read time 2 minutesLast updated 12 days ago
You can use code to perform interactions between plug-ins and your Unity code. The following examples show how to call various types of functions from JavaScript and C/C++/C# code in your Unity project.
Call JavaScript code in Unity C# example
The following code is an example of JavaScript code that your Unity C# script can call functions from.
mergeInto(LibraryManager.library, { Hello: function () { window.alert("Hello, world!"); }, HelloString: function (str) { window.alert(UTF8ToString(str)); }, PrintFloatArray: function (array, size) { for(var i = 0; i < size; i++) console.log(HEAPF32[(array >> 2) + i]); }, AddNumbers: function (x, y) { return x + y; }, StringReturnValueFunction: function () { var returnStr = "bla"; var bufferSize = lengthBytesUTF8(returnStr) + 1; var buffer = _malloc(bufferSize); stringToUTF8(returnStr, buffer, bufferSize); return buffer; }, BindWebGLTexture: function (texture) { GLctx.bindTexture(GLctx.TEXTURE_2D, GL.textures[texture]); },});
The following code is an example of Unity C# code that calls the functions defined in the JavaScript example.
using UnityEngine;using System.Runtime.InteropServices;public class NewBehaviourScript : MonoBehaviour { [DllImport("__Internal")] private static extern void Hello(); [DllImport("__Internal")] private static extern void HelloString(string str); [DllImport("__Internal")] private static extern void PrintFloatArray(float[] array, int size); [DllImport("__Internal")] private static extern int AddNumbers(int x, int y); [DllImport("__Internal")] private static extern string StringReturnValueFunction(); [DllImport("__Internal")] private static extern void BindWebGLTexture(int texture); void Start() { Hello(); HelloString("This is a string."); float[] myArray = new float[10]; PrintFloatArray(myArray, myArray.Length); int result = AddNumbers(5, 7); Debug.Log(result); Debug.Log(StringReturnValueFunction()); var texture = new Texture2D(1, 1, TextureFormat.ARGB32, false); BindWebGLTexture(texture.GetNativeTexturePtr()); }}
Call C/C++/C# code in Unity C# scripts example
The following code is an example C++ plug-in with simple functions that you can call in your Unity project.
#include <stdio.h>extern "C" void Hello (){ printf("Hello, world!\n");}extern "C" int AddNumbers (int x, int y){ return x + y;}
Then, use the following Unity C# code in your Unity project to call the C++ functions.
using UnityEngine;using System.Runtime.InteropServices;public class NewBehaviourScript : MonoBehaviour { [DllImport("__Internal")] private static extern void Hello(); [DllImport("__Internal")] private static extern int AddNumbers(int x, int y); void Start() { Hello(); int result = AddNumbers(5, 7); Debug.Log(result); }}