lodash.once

What is lodash.once?

The lodash.once package is a utility that allows you to create a function that can only be called once. After the first call, subsequent calls to the function will return the result of the first call without executing the function again. This is useful for initializing resources or other actions that should only happen once.

What are lodash.once's main functionalities?

Creating a function that can only be called once

This feature allows you to create a function that will only execute its body once and will return the result of the first execution on subsequent calls.

const once = require('lodash.once');
const initialize = once(() => {
  console.log('Initialization complete.');
  return 'Initialized';
});

console.log(initialize()); // Output: Initialization complete.
console.log(initialize()); // Output: Initialized (without logging 'Initialization complete.' again)

Other packages similar to lodash.once

once

The 'once' package provides a similar functionality to lodash.once, allowing you to ensure a function can only be executed once. It is a standalone package that is not part of the lodash library, which might be preferable for those looking to avoid additional dependencies.

memoizee

While 'memoizee' is primarily a memoization library, it can be used to achieve a similar effect to lodash.once by memoizing a function with no arguments. The difference is that memoizee offers more advanced features like cache expiration and primitive handling.

README

lodash.once v3.0.1

The modern build of lodash’s _.once exported as a Node.js/io.js module.

Installation

Using npm:

$ {sudo -H} npm i -g npm
$ npm i --save lodash.once

In Node.js/io.js:

var once = require('lodash.once');

See the documentation or package source for more details.