# defaults > A simple one level options merge utility ## Install ```sh npm install defaults ``` ## Usage ```js const defaults = require('defaults'); const handle = (options, fn) => { options = defaults(options, { timeout: 100 }); setTimeout(() => { fn(options); }, options.timeout); } handle({timeout: 1000}, () => { // We're here 1000 ms later }); handle({timeout: 10000}, () => { // We're here 10s later }); ``` ## Summary this module exports a function that takes 2 arguments: `options` and `defaults`. When called, it overrides all of `undefined` properties in `options` with the clones of properties defined in `defaults` Sidecases: if called with a falsy `options` value, options will be initialized to a new object before being merged onto.