How to truncate a string at full words in JavaScript

In this Article we will go through how to truncate a string at full words 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 truncate = (str, max, suffix) => str.length < max ? str : `${str.substr(0, str.substr(0, max - suffix.length).lastIndexOf(' '))}${suffix}`;

truncate('This is a long message', 20, '...');  // 'This is a long...'