lodash.cond

What is lodash.cond?

The lodash.cond package is a utility function from the Lodash library that allows you to create a function that iterates over pairs of predicates and functions, invoking the function of the first predicate to return truthy. This is useful for creating conditional logic in a functional programming style.

What are lodash.cond's main functionalities?

Conditional Function Execution

This feature allows you to create a function that executes different logic based on the input. The function `func` will return 'one' if the input is 1, 'two' if the input is 2, and 'default' for any other input.

const _ = require('lodash.cond');

const func = _.cond([
  [x => x === 1, () => 'one'],
  [x => x === 2, () => 'two'],
  [() => true, () => 'default']
]);

console.log(func(1)); // 'one'
console.log(func(2)); // 'two'
console.log(func(3)); // 'default'

Other packages similar to lodash.cond

ramda

Ramda is a functional programming library for JavaScript that provides a similar `cond` function. Ramda's `cond` function works in a similar way to lodash.cond, allowing you to create a function that iterates over pairs of predicates and functions. Ramda is known for its strong emphasis on immutability and functional programming principles.

underscore

Underscore is another utility library that provides functional programming helpers. While it does not have a direct equivalent to lodash.cond, it offers a variety of utility functions that can be combined to achieve similar conditional logic. Underscore is often compared to Lodash, with Lodash being considered a more modern and feature-rich alternative.

README

lodash.cond v4.5.2

The lodash method _.cond exported as a Node.js module.

Installation

Using npm:

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

In Node.js:

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

See the documentation or package source for more details.