JSFiddle - React, Tailwind, and code Playground

HTML

<div class='item'>
    <h1 id="Python">Python</h1>
</div>

<div class='item'>
    <h1 id="C++">C++</h1>
</div>

<div class='item'>
    <h1 id="PHP">PHP</h1>
</div>

JavaScript

var myList = document.getElementsByTagName('h1');
var languages = [];
for( var i=0; i<myList.length; i++){
    languages.push( myList[i].innerHTML );
}

console.log( languages );