JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://ivaynberg.github.io/select2/select2-3.4.5/select2.js"></script>
<link rel="stylesheet" href="//netdna.bootstrapcdn.com/font-awesome/4.0.3/css/font-awesome.css">
<link rel="stylesheet" href="//ivaynberg.github.io/select2/select2-3.4.5/select2.css">
<select id="sel" style="width: 100%">
    <option value="1">Hello</option>
    <option value="2">Friends</option>
    <option value="3">Stackoverflow</option>
</select>

JavaScript

/* var icon_checked = "<i class='fa fa-check'></i>";

function format(opt) {
    var selection = this.element.select2("val");

    if (opt.id === selection) {
        return opt.text + icon_checked;

    }
    return opt.text;
}
 */
$("#sel").select2({
    /* formatResult: format */
});