javascript - Why should "this" be assigned to variable in jQuery? -

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In some jQuery code I often think that this is assigned to the variable in jQuery and I do not understand the reason for this approach?

This is an example of a jQuery plugin builder: 

  // constructor function Nullpoll (element, option) {var widget = this; Widget.config = $ .extend ({}, default, options); Widget.element = element; Widget.element.on ("click", function () {alert ("test")}; Widget.element.one ("change", function (e) {widget.element.find ("button"). RemoveProp ("disabled");}); This.init (); }

The value of this is determined by how <

  1. or
  2. (more commonly) to give it a more informative name so that value one different Function , which can reach the scope of the first function

In this particular case, widget.element.one () Near anonymously function call this call to call Nullpoll . If it tries to use the this keyword, then it will get a different value (how the value depends on whether a a function is called a mismatch function) < / P>


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