JSFiddle - React, Tailwind, and code Playground
HTML
<h2 id="head1" class="head"> here is some interesting links </h2>
<a class="aExpand" href="#">+</a>
<ul class="sub" style="display:none;">
<li>link 1</li>
<li>link 2</li>
<li>link 3</li>
</ul>
JavaScript
$(function(){
$(".aExpand").click(function(e){
var item=$(this);
if(item.next("ul").is(":visible"))
{
item.text("+").next("ul").hide();
}
else
{
item.text("-").next("ul").show();
}
});
});