JSFiddle - React, Tailwind, and code Playground

HTML

<select name="test">
    <option value="stack">Stack</option>
    <option value="overflow">Overflow</option>
    <option value="my">My</option>
    <option value="question">Question</option>
</select>
<div id="log"></div>
<div id="log1"></div>

JavaScript

(function () {
    var previous;
    var count = 1;

    $("select[name=test]").focus(function () {
        // Store the current value on focus, before it changes
        previous = this.value;
    }).change(function() {
        // Do soomething with the previous value after the change
        document.getElementById("log").innerHTML = "<b>Previous: </b>"+previous;
        document.getElementById("log").innerHTML = "<b>Previous: </b>"+previous;
        
        previous = this.value;
    });
})();