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OOP and first class functions question

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  OOP and first class functions question bit-naughty@hotmail.com - 2014-06-02 11:41 -0700
    Re: OOP and first class functions question Scott Sauyet <scott.sauyet@gmail.com> - 2014-06-02 12:25 -0700
      Re: OOP and first class functions question bit-naughty@hotmail.com - 2014-06-03 06:03 -0700

#24579 — OOP and first class functions question

If I have var x = function() { whatever}, and I then say var p =x , can I then say var newobj = new p(); ? And then will everything inside x be available like eg. newobj.method?



Thanks.

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#24580

bit-naughty@hotmail.com wrote:
> If I have var x = function() { whatever}, and I then say var p =x , 
> can I then say var newobj = new p(); ? And then will everything 
> inside x be available like eg. newobj.method? 

Yes.

    var Rectangle = function(w, h) {this.width = w; this.height = h;}; 
    Rectangle.prototype.area = function() {return this.width * this.height;};
    var Rect = Rectangle;
    var box = new Rect(3, 5);
    box.area(); //=> 15  // It works!
    
The function is a first-class item in the Javsacript ecosphere.  The variable
`Rectangle` used to hold a reference to that function is just that.  You can
add another reference, such as `Rect`, and that function will still behave
as before.  You could even then reset the original reference, and the new one
would continue to function:

    Rectangle = null;
    var r = new Rectangle(2, 6); //=> TypeError
    var r = new Rect(2, 6);
    r.area(); //=> 12

HTH,

  -- Scott

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#24591

Thanks, Scott! :)

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