JSFiddle - React, Tailwind, and code Playground

HTML

<div id="testHarness"></div>

<button id="test1" onClick="testFirst(this)">Tetst 1 with data</button>
<button id="test2" onClick="testSecond(this)">Tetst 2 with data</button>

<button onClick="testFirst(this)">Tetst 1 NO data</button>

<button onClick="testSecond(this)">Tetst 2 NO data</button>

JavaScript

testFirst = function (data){
        if(data !== null)
            $('#testHarness').text(data.id);
    }
    
    testSecond = function(data){
        if(data !== "")
            $('#testHarness').text(data.id);
    }