The role and difference of $.extend and $.fn.extend of jquery

jquery has two methods for developing plug-ins, namely:

JQuery.fn.extend ();

Jquery.extend ();

Although JavaScript does not have a clear class concept, it is more convenient to use a class to understand it. jquery is a well-encapsulated class, such as we use the statement $ ("#btn1") to generate an instance of the jquery class.

Jquery.extend (object); Add a " static method"to the jquery class. Such as:

1 jquery.extend ({2     functionreturn a < b a:b;},3     function return a > B? a:b;} 4 }); 5 //   26//  5

Static MethodsJquery.Extend(Target, Object1, [OBJECTN]) to extend an object with one or more other objects, returning the object being extended

1 var false, Limit:5, Name: "foo" }; 2 var true, Name: "Bar" }; 3 jquery.extend (settings, options); 4 true, Limit:5, Name: "Bar"}

extension Methods

JQuery.fn.extend (object); The extension to Jquery.prototype is to add " member functions " to the jquery class. An instance of the jquery class can use this "member function".

For example, we want to develop a plugin, make a special edit box, when it is clicked, then alert the contents of the current edit box. You can do this:

1 $.fn.extend ({          2      alertwhileclick:function() {            3            $ ( this). Click (function() {                 4                   alert ($ (this). Val ());            5             });            6       }       7

member Methods$ ("#input1"). Alertwhileclick (); On the page is:

$ ("#input1") is a jquery instance, and when it calls the Member method Alertwhileclick, it implements the extension, which pops up the contents of the current edit each time it is clicked.

The role and difference of $.extend and $.fn.extend of jquery