JSFiddle - React, Tailwind, and code Playground

HTML

<label>Enter Name:</label><input type="text" id="name" />
<button id="submit">Submit</button><button id="showAll">Show All</button>
<div id="output"></div>

JavaScript

var allNames = [];

document.getElementById("submit").onclick = function()
{
    var name = document.getElementById("name").value;
    document.getElementById("output").innerHTML = "Your name is "+name;
    allNames.push(name);    
}

document.getElementById("showAll").onclick = function()
{
    var names = "Names: ";
    for(name in allNames) names += allNames[name] + ", ";
    document.getElementById("output").innerHTML = names;
}