lodash difference between a-b code example

Example 1: how to collect keys using lodash javascript

import * as _ from 'lodash';

const objectMap = {'key1': 'value1', 'key2': 'value2'};
const allKeys = _.keys(objectMap); //Returns a string[]. Here it will be ['key1','key2'];

Example 2: lodash map

const _quote_filter = _.map(quote_state, (val, key) => {   if (val) {      return key   }})console.log(_quote_filter) //=> [ 'btc', undefined, undefined ]