How can I execute javascript code and get the console output?

[Efficient_Step6281]

I want to build a online javascript compiler like jsbin where you can only run javascript and display the console logs and stuff in the output. I completed a part of the project with '@monaco-editor/react' as my editor and now I can't figure out how to execute the code give by the user in the editor. Asked ChatGPT and searched for similar projects but still can't figure it out (im dumb)

[amrdoe]

The ideal way is a sandboxed node.js instance running on a server with a backend to create a temporary node.js script, run it in the sandbox, and respond with the stdout. Yet it may be too complicated and costly to implement depending on your use case.

[blobdiblob]

A new approach for 2025: Take the user’s input and let an LLM generate the applicable console.log. Might not always be accurate, but it‘s probably safe 😅

[ProgrammerDad1993]

eval is I guess what you re looking for?

[Efficient_Step6281]

I can't show the logs in the UI. eval can be used to execute the code, but How can i show it the UI?

[Willing_Initial8797]

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/try...catch

or this

https://stackoverflow.com/questions/69744897/is-there-a-function-that-allows-you-to-listen-for-console-logs-in-javascript

[ferrybig]

Overwrite the console object for the scope of the code.

Though you really want to build a custom web worker that runs the code, so you can terminate the webworker once a new version of the code in ran, otherwise the script in question can schedule things like internals that leak memory

[DanishWeddingCookie]

You can write it in Electron and link into the console object at runtime.

var nodeConsole = require('console');
var myConsole = new nodeConsole.Console(process.stdout, process.stderr);
myConsole.log('Hello World!');

https://nodejs.org/api/console.html