> ## Documentation Index
> Fetch the complete documentation index at: https://docs.codecrafters.io/llms.txt
> Use this file to discover all available pages before exploring further.

# JavaScript

> Learn how to solve CodeCrafters challenges in JavaScript

## Local development

To run the code for your challenge locally, you'll need `node` installed. Our test runners use Node 18 (as of April 2024).

The script for your challenge (like `./your_grep.sh`) will automatically compile your code using `node` before executing it. It'll
look something like this:

```sh theme={null}
#!/bin/sh

exec node app/main.js "$@"
```

## File structure

* The files for your solution are placed in the `app/` directory.
* `app/main.js` contains the `main()` function, which is what the test runner executes.

## Adding more files

You can add more files and directories to `app/`. The test runner will include them when compiling your code.

For example, if you add a file at `app/foo.js`, you could use it like so:

<CodeGroup>
  ```javascript app/foo.js theme={null}
  function foo() {
      console.log('Hello from foo!');
  }

  function bar() {
      console.log('Hello from bar!');
  }

  module.exports = { foo, bar };
  ```

  ```javascript app/main.js theme={null}
  const { foo, bar } = require('./foo');

  function main() {
      foo();  // Uses the foo function from foo.js
      bar();  // Uses the bar function from foo.js
  }
  ```
</CodeGroup>

<Note>We use the CommonJS syntax for importing and exporting of modules.</Note>

## Adding dependencies

You can add dependencies to your project using `npm`.

<Note>Instructions for adding depedencies will be documented soon.</Note>