JSFiddle - React, Tailwind, and code Playground

HTML

<form name="dummyForm">
    <select name="selectBox" id="selectBox" onchange="changeSelectedvalue()">
        <option value="option 1">option 1</option>
        <option value="option 2">option 2</option>
        <option value="option 3">option 3</option>
        <option value="option 4">option 4</option>
        <option value="option 5">option 5</option>
        <option value="option 6">option 6</option>
        <option value="option 7">option 7</option>
        <option value="option 8">option 8</option>
    </select>
</form>

<script>
$(function() {
window.onload = function()
{
    var cookieVal = readCookie('selectBoxValue');
    if(cookieVal!=null)
    {
        document.getElementById('selectBox').selectedIndex = cookieVal;
    }
}



function changeSelectedvalue()
{
    var mySelectedIndex = document.getElementById('selectBox').selectedIndex;
    createCookie("selectBoxValue",mySelectedIndex,1000);
}



function createCookie(name,value,days) {
	if (days) {
		var date = new Date();
		date.setTime(date.getTime()+(days*24*60*60*1000));
		var expires = "; expires="+date.toGMTString();
	}
	else var expires = "";
	document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
	var nameEQ = name + "=";
	var ca = document.cookie.split(';');
	for(var i=0;i < ca.length;i++) {
		var c = ca[i];
		while (c.charAt(0)==' ') c = c.substring(1,c.length);
		if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
	}
	return null;
}

function eraseCookie(name) {
	createCookie(name,"",-1);
}

});
</script>