How to find the maximum item of an array by given key in JavaScript

In this Article we will go through how to find the maximum item of an array by given 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 maxBy = (arr, key) => arr.reduce((a, b) => a[key] >= b[key] ? a : b, {});

const people = [
    { name: 'Bar', age: 24 },
    { name: 'Baz', age: 32 },
    { name: 'Foo', age: 42 },
    { name: 'Fuzz', age: 36 },
];
maxBy(people, 'age');   // { name: 'Foo', age: 42 }