JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="inp">
<button class="btn">Push to array</button>
<br><br>
<div id="list"></div>

JavaScript

var inp = document.getElementById("inp");
var btn = document.querySelector(".btn");
var list = document.querySelector('#list');
var arr = [];

btn.addEventListener('click', function(str) {
  var valInp = inp.value;
  arr.push(valInp);
  inp.value = "";
  list.innerHTML = arr.join(" "); 

});