JavaScript method/Binding Unbind Event

Many JS plug-ins begin with the Code (function ( which is not quite clear until you see

 //  Event Bindings  this.bindHandler =  (function ()  {                  if  (Window.addeventlistener)  {//   Standard browser           return function (Elem, type,  handler)  {// elem: node     type: Event Type    handler: event handler                //  the last parameter is true: Call event handlers in the capture phase      false: Invoke event handlers in the bubbling phase                elem.addeventlistener (Type, handler, false);          }    } else if  (window.attachevent)  {// ie Browser          return function (elem, type ,  handler)  {   &NBSp;          elem.attachevent ("On"  + type,  Handler) (          }    }) ();         //  Event Cancellation this.removehandler =  (function ()  {                 if  ( Window.removeeventlisterner)  {//  Standard browser         return  function (Elem, type, handler)  {             elem.removeeventlisterner (Type, handler, false);         }     } else if  (window.detachevent)  {// ie Browser           return function (Elem, type, handler )  {     &NBsp;        elem.detachevent ("on"  + type, handler);           }     }) ();

Simplification into

A = (function () {return function (b) {alert (b);  } })(); A (' $b $ ');

It's clear at one glance: The return value of the call function is the closure function

JavaScript method/Binding Unbind Event