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module / module.exports

The CommonJS module object whose exports define the public API of a file.

Since Node 0.x Spec ↗

Syntax

module.exports = value  /  exports.name = value

Returns

object — The current module record; module.exports is what require() returns.

Examples

// math.js (CommonJS)
function add(a, b) { return a + b; }
module.exports = { add };

// main.js
const { add } = require('./math');
console.log(add(2, 3));
Output 
5

// Detect if run directly vs. required
if (require.main === module) {
  console.log('run as a script');
}
Output 
run as a script

Notes

Reassigning `module.exports` replaces the entire export; `exports.x` only adds a property and breaks if you also reassign `exports`. The ESM equivalent is `export`/`export default`; the `require.main === module` idiom maps to checking `import.meta.main` in newer Node.

See also