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

Call functions from your C or C++ code in your Unity project.
Read time 2 minutesLast updated 13 days ago
You can call functions from your C, C++, or C# plug-ins in your Unity projects.
Unity uses Emscripten to compile your sources into WebAssembly from C/C++/C# code, so you can write plug-ins in C/C++/C# code and call these functions from your Unity C# scripts.
To call functions from your JavaScript plug-ins instead, refer to Call JavaScript functions from Unity C# scripts.

Import your C/C++/C# plug-in into your Unity project

To allow your Unity project to call functions from your C/C++/C# plug-in code, you need to import your plug-in into your Unity project.
Place your JavaScript plug-in files in any folder, such as 
Assets/JSPlugins
.

Example C++ code that you can use in Unity

If you use C++ (.cpp) to implement the plug-in, you must declare the functions with C linkage (
extern “C”
) to avoid name mangling issues. 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;}
Note
Unity uses the Emscripten version 2.0.19 toolchain.
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);      }}

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