lodash array unique code example

Example 1: lodash unique array of objects

var users = [
  {id:1,name:'ted'},
  {id:1,name:'ted'},
  {id:1,name:'bob'},
  {id:3,name:'sara'}
];
var uniqueUsersByID = _.uniqBy(users,'id'); //removed if had duplicate id
var uniqueUsers = _.uniqWith(users, _.isEqual);//removed complete duplicates

Example 2: lodash unique array

_.uniq([2, 1, 2]);
// => [2, 1]
 
// using `isSorted`
_.uniq([1, 1, 2], true);
// => [1, 2]
 
// using an iteratee function
_.uniq([1, 2.5, 1.5, 2], function(n) {
  return this.floor(n);
}, Math);
// => [1, 2.5]
 
// using the `_.property` callback shorthand
_.uniq([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }, { 'x': 2 }]

Example 3: lodash deep clone object

const clone = require('lodash/clone'); 
const cloneDeep = require('lodash/clonedeep');

const shallowCopy = clone(originalObject);
const deepCopy = clonedeep(originalObject);

Example 4: lodash find duplicate element index

const _ = require('lodash');
let arr = ["a", "a", "b", "c", "c", "a"];

let result = _.omitBy(
  _.reduce(arr, (a, v, i) => _.set(a, v, (a[v] || []).concat([i])), {} ),
  v => v.length <= 1
);

console.log(result);

Example 5: lodash map

_.each(markets, (obj, key) => {   obj.symbol = key})console.log(markets)//=> {       'BTC/USD': { buys: 0, sells: 3, symbol: 'BTC/USD' },       'DASH/BTC': { buys: 3, sells: 1, symbol: 'DASH/BTC' },       'ETH/BTC': { buys: 3, sells: 2, symbol: 'ETH/BTC' }    }