JSFiddle - React, Tailwind, and code Playground
HTML
<ul class="boxes_tree" id="tree">
<li><strong>data</strong></li>
</ul>
JavaScript
var itemStr ='[{"var":"data1"},{"var":"data2"}]';
itemStr=$.parseJSON(itemStr);
var UL = $("#tree");
if(itemStr){
$(itemStr).each(function(i, val) {
UL.append("<li>"+val.var+"</li>");
});
}