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Cons in the following object implementation

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  Cons in the following object implementation Alon Melanker <melankeril@gmail.com> - 2014-02-10 04:21 -0800
    Re: Cons in the following object implementation "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-02-10 13:33 +0100
      Re: Cons in the following object implementation Alon Melanker <melankeril@gmail.com> - 2014-02-10 05:22 -0800
    Re: Cons in the following object implementation Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-02-10 14:53 +0100

#23049 — Cons in the following object implementation

On a job interview, I've been asked to defined an object with a private variable and getter/setter for this private variable.

I chose the following:

var obj = function() {
   var private;
   
   this.setPrivate(val) {
      private = val;
   }
   
   this.getPrivate() {
      return private;
   }
};


When I've finished to implement the object the interviewer told me there are some problems\cons with this object and those "problems" are not the setter/getter functions.

I've been asked to point out those flaws, but I couldn't.

Does anyone can point out the flaws in the object?  
   
   
  

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#23050

Alon Melanker <melankeril@gmail.com> wrote on 10 feb 2014 in
comp.lang.javascript: 

> On a job interview, I've been asked to defined an object with a private
> variable and getter/setter for this private variable. 
> 
> I chose the following:
> 
> var obj = function() {
>    var private;
>    
>    this.setPrivate(val) {
>       private = val;
>    }
>    
>    this.getPrivate() {
>       return private;
>    }
>};

Didn't you ask this before?

> When I've finished to implement the object the interviewer told me there
> are some problems\cons with this object and those "problems" are not the
> setter/getter functions. 
> 
> I've been asked to point out those flaws, but I couldn't.
> 
> Does anyone can point out the flaws in the object?  

<http://stackoverflow.com/questions/11258201/what-does-this-mean-in-
javascript-var-obj-function>


-- 
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

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#23052

On Monday, February 10, 2014 2:33:56 PM UTC+2, Evertjan. wrote:
> Alon Melanker <melankeril@gmail.com> wrote on 10 feb 2014 in
> 
> comp.lang.javascript: 
> 
> 
> 
> > On a job interview, I've been asked to defined an object with a private
> 
> > variable and getter/setter for this private variable. 
> 
> > 
> 
> > I chose the following:
> 
> > 
> 
> > var obj = function() {
> 
> >    var private;
> 
> >    
> 
> >    this.setPrivate(val) {
> 
> >       private = val;
> 
> >    }
> 
> >    
> 
> >    this.getPrivate() {
> 
> >       return private;
> 
> >    }
> 
> >};
> 
> 
> 
> Didn't you ask this before?
> 
> 
> 
> > When I've finished to implement the object the interviewer told me there
> 
> > are some problems\cons with this object and those "problems" are not the
> 
> > setter/getter functions. 
> 
> > 
> 
> > I've been asked to point out those flaws, but I couldn't.
> 
> > 
> 
> > Does anyone can point out the flaws in the object?  
> 
> 
> 
> <http://stackoverflow.com/questions/11258201/what-does-this-mean-in-
> 
> javascript-var-obj-function>
> 
> 
> 
> 
> 
> -- 
> 
> Evertjan.
> 
> The Netherlands.
> 
> (Please change the x'es to dots in my emailaddress)

Hi,

This is not my question on stack.
Anyway I don't see how does this answer my question.

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#23053

Alon Melanker wrote:

> On a job interview, I've been asked to defined an object with a private
> variable and getter/setter for this private variable.
> 
> I chose the following:
> 
> var obj = function() {
>    var private;
>    
>    this.setPrivate(val) {
>       private = val;
>    }
>    
>    this.getPrivate() {
>       return private;
>    }
> };
> 
> 
> When I've finished to implement the object the interviewer told me there
> are some problems\cons with this object and those "problems" are not the
> setter/getter functions.
> 
> I've been asked to point out those flaws, but I couldn't.
> 
> Does anyone can point out the flaws in the object?

This program is syntactically in error, which you would have known if you 
had tried to run it before you asked.

If one mentally corrected the syntax errors, it would still be 
*semantically* in error, which you had known if you knew the first thing 
about these languages: “obj” would refer to a *Function* instance that, when 
called in non-strict mode, returned “undefined”; a function that, when 
called in strict mode, would throw a ReferenceError exception because “this” 
would be “undefined”.

The correct code – also called the Module Pattern – is

  var obj = (function () {
    /* The underscore for privates is a matter of preference only */
    var _private;
   
    return {
      setPrivate: function (val) {
        _private = val;
      },
   
      getPrivate: function () {
        return _private;
      }
    };
  }());

You should not consider applying for another job of this kind before you 
have understood and can explain in correct terminology why this is the 
correct code.  This is _not_ “JavaScript 101”.  Do your own homework.

<http://PointedEars.de/faq#posting>

-- 
PointedEars

Twitter: @PointedEars2
Please do not Cc: me. / Bitte keine Kopien per E-Mail.

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