In this Article we will go through how to group an array of objects by a key only using single line of code in JavaScript.
This is a one-line JavaScript code snippet that uses one of the most popular ES6 features => Arrow Function.
Let's define this short function:
const groupBy = (arr, key) => arr.reduce((acc, item) => ((acc[item[key]] = [...(acc[item[key]] || []), item]), acc), {});
groupBy([
{ branch: 'audi', model: 'q8', year: '2019' },
{ branch: 'audi', model: 'rs7', year: '2020' },
{ branch: 'ford', model: 'mustang', year: '2019' },
{ branch: 'ford', model: 'explorer', year: '2020' },
{ branch: 'bmw', model: 'x7', year: '2020' },
], 'branch');
/*
{
audi: [
{ branch: 'audi', model: 'q8', year: '2019' },
{ branch: 'audi', model: 'rs7', year: '2020' }
],
bmw: [
{ branch: 'bmw', model: 'x7', year: '2020' }
],
ford: [
{ branch: 'ford', model: 'mustang', year: '2019' },
{ branch: 'ford', model: 'explorer', year: '2020' }
],
}
*/