map for nulls descending

const _ = require('lodash'); const data = [ { exemplar: "Bill", ranking: 20 }, { exemplar: "Fred", ranking: 45 }, { exemplar: "Mike", ranking: null }, { exemplar: "Jane", ranking: 80 }, { exemplar: "John", ranking: 15 }, { exemplar: "Alex", ranking: null }, { exemplar: "Andy", ranking: 40 }, { exemplar: "Anna", ranking: null }, { exemplar: "Jess", ranking: 92 }, ]; const mapping = (item) => { let sortKey = item.ranking || -99999; return { sortKey, ...item }; } const compare = (a, b) => { if (a.sortKey > b.sortKey) { return -1; } else if (b.sortKey > a.sortKey) { return 1; } return 0; } data.map(mapping).sort(compare);