JSFiddle - React, Tailwind, and code Playground

HTML

<a href='test' id="test-id">truncate this text</a>

JavaScript

function truncate(id){
    var string = document.getElementById(id).innerHTML;
    if (string.length > 5) {
        document.getElementById(id).innerHTML = string.substring(0,5)+'...';
    }
};

truncate("test-id");