Calling JavaScript Functions from C/C++

So far you have called C/C++ from JavaScript. But WASM code often needs to reach back into JS, to log, manipulate the DOM, or call browser APIs.

Emscripten provides several ways for your C/C++ code to call JavaScript.

WASM is sandboxed, it cannot touch the DOM, fetch, or timers directly. Anything outside pure computation must go through JavaScript.

• Update the page
• Read user input
• Use Web APIs like localStorage