Javascript question on inheritance and prototypes

Question

In jQuery library I found this line

jQuery.extend = jQuery.fn.extend = function() {

This kind of puzzle is me. I thought that this object automatically provides access to its prototype methods (in other words, if the method or var is not allowed on the object itself, it is checked on its prototype, then on the prototype prototype, etc.).

So, what is the reason for associating a function with both an object and a prototype? (in jQuery fn is a prototype alias).

Answer 1

Magic prototypeis a property of constructors, not objects. The jQuery instance inherits extendfrom the prototype, but jQuery needs its own copy.

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§ 4.2.1, :

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