How to check if a number is negative in JavaScript

In this Article we will go through how to check if a number is negative 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 isNegative = number => Math.sign(number) === -1;

const isNegative = number => number < 0;

isNegative(-3);     // true
isNegative(8);      // false