JSFiddle - React, Tailwind, and code Playground

HTML

<div id="jo">
    <div id="jo1"></div>
    <div id="jo2"></div>
    <div id="jo3"></div>
</div>
<div id="res"></div>

JavaScript

(function ($){
    var $jo = $('#jo');
    var $res = $('#res');
    var arrChild = [];
    
    addChild($jo, arrChild);//
             
    function addChild(a,b){
        a.children().each( function (i,e) {
          b.push( $(e).attr('id') );
        });
    }
    $res.append("Array: [" + arrChild + "]");
})(jQuery);