JSFiddle - React, Tailwind, and code Playground

HTML

<div id="div1"></div>
<div id="div2"></div>

JavaScript

(function($) {
      $.fn.test = function() {

        return this.each(function() {
          var x = false;
          
          alert(x);

          if (!x) {
            x = true;
          } 
        });
      }
    }(jQuery));

    $("#div1").test();  //false
    $("#div2").test();  // false