$devvkit learn --librarie lodash-guide

Lodash Guide

[utilities][data]

JavaScript / TypeScript

Install

npm install lodash
npm install -D @types/lodash

Lodash provides consistent, modular functions for common programming tasks.

Key utilities: cloneDeep, merge, debounce, groupBy, orderBy, keyBy.

Lodash v5 is tree-shakeable. Import only what you need.

Arrays

Chunk· Split array into groups.

import chunk from 'lodash/chunk';
chunk(['a','b','c','d'], 2); // [['a','b'],['c','d']]

Uniq by· Remove duplicates.

import uniqBy from 'lodash/uniqBy';
uniqBy([{id:1},{id:1},{id:2}], 'id');

Group by· Group by key.

import groupBy from 'lodash/groupBy';
groupBy([{role:'admin'},{role:'user'}], 'role');

Order by· Sort by criteria.

import orderBy from 'lodash/orderBy';
orderBy(users, ['age','name'], ['asc','desc']);

Pick· Select keys.

import pick from 'lodash/pick';
pick({name:'Alice', age:30, password:'secret'}, ['name','age']);

Omit· Exclude keys.

import omit from 'lodash/omit';
omit({name:'Alice', password:'secret'}, ['password']);

Debounce· Delay invocation.

import debounce from 'lodash/debounce';
const save = debounce((text) => api.save(text), 500);

Throttle· Limit invocation rate.

import throttle from 'lodash/throttle';
window.addEventListener('scroll', throttle(() => console.log('scroll'), 200));

Clone deep· Deep clone with circular ref support.

import cloneDeep from 'lodash/cloneDeep';
const clone = cloneDeep(original);
clone.nested.a = 2; // original unchanged

Merge· Deep merge objects.

import merge from 'lodash/merge';
merge({ theme: { dark: false } }, { theme: { dark: true } });

Is equal· Deep comparison.

import isEqual from 'lodash/isEqual';
isEqual({a:1,b:{c:2}}, {a:1,b:{c:2}}); // true