JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li class="one">Element One</li>
    <li class="two">Element Two</li>
    <li class="one">Element Three</li>
    <li class="two">Element Four</li>
    <li class="one">Element Five</li>
    <li class="two">Element Six</li>
</ul>

CSS

.one {
    background-color: yellow;
}
.two {
    background-color: blue;
}

JavaScript

var stringArray = [];
$('.one, .two').each(function(i, v) {
  stringArray.push( $(v).html() );
});
var jsonString = JSON.stringify(stringArray);

console.log(jsonString);