What is WebAssembly

WebAssembly (WASM) is a low-level binary instruction format that allows developers to run code written in languages other than JavaScript on the web. It’s designed to be fast, efficient, and portable, and can be used to bring performance-critical parts of an application to the web.

WebAssembly is designed to be a complement to JavaScript, not a replacement. It allows developers to write parts of their application in languages such as C, C++, or Rust that are more efficient at certain tasks, and then run them alongside JavaScript code in the browser. This can lead to significant performance improvements for certain types of applications, such as games, video editing, and scientific simulations.

To use WebAssembly in a web application, developers must first write their code in a language that can be compiled to WebAssembly, such as C, C++, Rust, or even Assembly. Then, they must use a tool such as Emscripten, Binaryen, or Rust’s wasm-bindgen to convert the code to a .wasm file, which can be loaded and run by the browser.

Here’s an example of how to use WebAssembly in a web application:

<script>
    // Fetch the .wasm file
    fetch('my_module.wasm').then(response =>
        response.arrayBuffer()
    ).then(bytes =>
        WebAssembly.instantiate(bytes)
    ).then(results => {
        // Get the exports object
        const myModule = results.instance.exports;

        // Call a function exported by the WebAssembly module
        console.log(myModule.add(1, 2)); // 3
    });
</script>

In this example, we’re using the fetch function to retrieve the my_module.wasm file, which contains the WebAssembly code we want to run. We then use the WebAssembly.instantiate function to convert the binary file into a JavaScript object that we can interact with. Once the module is instantiated, we can access the functions exported by the WebAssembly module, such as the add function in this example.

It’s important to note that WebAssembly is still a relatively new technology and not all browsers currently support it. However, it is widely supported in all major browsers such as Chrome, Firefox, Safari, Edge and Opera, so it’s still possible to use WebAssembly in production.

Conclusion

In conclusion, WebAssembly is a binary instruction format that allows developers to run code written in languages other than JavaScript on the web. It is designed to be fast, efficient, and portable and can be used to bring performance-critical parts of an application to the web. WebAssembly is a complement to JavaScript, not a replacement and can be used to improve performance for certain types of applications, such as games, video editing, and scientific simulations. Developers must write the code in a language that can be compiled to WebAssembly and use tools such as Emscripten, Binaryen, or Rust’s wasm-bindgen to convert it to a .wasm file that can be loaded by the browser and run.