ArrowFunction.js

$('document').ready( function(){
  
  //WITHOUT ARROW FUNCTION
  $('.my-name').on('click', function() {
      
       var that = this;
       setTimeout( function() {
           $(that).toggleClass('on');
       }, 1000);
      
  });
  
  
  //WITH ARROW FUNCTION
  $('.my-name').on('click', function() {
    
    setTimeout( () => {
      $(this).toggleClass('on');
    }, 1000);
    
  });
  
  
});