jquery implements $.fn.extend and $.extend functions _jquery

We extended the Bind method and the Ready function, and this time I'll talk about the $.fn.extend and $.extend functions.

Other not to say, directly into the theme bar!

Let's take a look at the difference between the two functions:

$.fn.extend is a method for node object extension of query, and is a method of prototype extension based on $

$.extend is a static method that extends the normal method and is $.

Let's look at the code we wrote before:

   (function (Win) {
      var _$ = function (selector, context) {return
        new _$.prototype. Init (selector, context);
      }
      _$.prototype = {
        Init:function (selector, context) {
  
        },
        Each:function (callback) {
 
        }      
      }
      _$. Prototype. Init.prototype = _$.prototype;       
      window.$ = window. JQuery = _$;
    }) (window);

This is the code for the principal.

I'm going to expand the $.fn.extend method first:

The idea of this method is that we can use $ ("") Newmetod () to access it after we extend it, which is actually adding a extend method to the $ prototype. The FN in the middle is actually similar to the role of the namespace, with little practical significance. In order to make a distinction with $.extend.

Familiar with the prototype of the fact that a look at it: let $.fn point to the prototype of $ not on the line?

So we have the following code: _$.FN = _$.prototype;

Next we'll add the Extend method:

  var isobj = function (o) {return
      Object.prototype.toString.call (o) = = "[Object Object]";
    }
    _$.fn.extend = function (obj) {
      if (isobj (obj)) {for
        (var i in obj) {
          this[i] = Obj[i];
        }
    }

The role of isobj in this code is to determine whether the incoming parameters are object objects, _$.fn.extend This method is actually the same as _$.prototype.extend, you see, this code may not be the same as the jquery source, I wrote it according to my own meaning.

Here's how to implement the $.extend method, which has just been said, is actually a static method for $, the code is as follows:

    $.extend = function (obj) {
        if (isobj (obj)) {for
          (var i in obj) {
            this[i] = Obj[i];
          }
      }

You will find that two methods are the same, but you have to think about it differently:

_$.fn.extend inside the This is actually representing $.prototype, $.extend inside of this represents is $.

These two methods have been implemented, with all the code:

 (function (Win) {
      var _$ = function (selector, context) {return
        new _$.prototype. Init (selector, context);
      }
      _$.prototype = {
        Init:function (selector, context) {

        },
        Each:function (callback) {

        }
      }
      _$. Prototype. Init.prototype = _$.prototype;
      _$.fn = _$.prototype;
      var isobj = function (o) {return
        Object.prototype.toString.call (o) = = "[Object Object]";
      }
      _$.fn.extend = function (obj) {
        if (isobj (obj)) {for
          (var i in obj) {
            this[i] = Obj[i];
          }
      }
      _$.extend = function (obj) {
        if (isobj (obj)) {for
          (var i in obj) {
            this[i] = Obj[i];
          }
      }
      window.$ = window. JQuery = _$;
    }) (window);

The use of the method is actually

$.fn.extend (

{

   method:function () {

}

})

$.extend (

{

   method:function ()

{}})

Code and jquery source is not the same, I this is to simplify the method of writing, we are mainly to ponder the idea inside, thank you for your reading.