Re: Why do I have to use the keyword this in my Employee example

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Message-ID	<1590346.McO4MUtrrQ@PointedEars.de> (permalink)
From	Thomas 'PointedEars' Lahn <PointedEars@web.de>
Reply-To	Thomas 'PointedEars' Lahn <cljs@PointedEars.de>
Organization	PointedEars Software (PES)
Date	Sat, 11 Jan 2014 20:07:20 +0100
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Subject	Re: Why do I have to use the keyword this in my Employee example
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Christoph Michael Becker wrote:

> John Harris wrote:
>> On Sat, 11 Jan 2014 13:08:29 +0100, "Tony Johansson"
>> <johansson.andersson@telia.com> wrote:
>> 
>>> <script type="text/javascript">
>>>   function Employee(first, last)
>>>   {
>>>       var _firstName = first;
>>>       var _lastName = last;
>>>
>> Those are *local* variables, hidden inside the Employee function. They
>> won't exist any more once Employee has returned.
> 
> That's not quite right.  Actually, the variables are part of the
> environment of the methods of Employee, if Employee is invoked as
> constructor (what happens in function Foo()).

Not quite correct; this applies only to these methods of Employee 
_instances_ and other functions defined in the context of Employee().
Key word: closure.

The methods of Employee instances here are “privileged“ and the variables 
are “private” (terms coined by Douglas Crockford, IIRC), because only those 
methods can access those variables/pseudo-properties.  It is the closest 
equivalent to private/protected properties in class-based OOP.

-- 
PointedEars

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

Thread

Why do I have to use the keyword this in my Employee example "Tony Johansson" <johansson.andersson@telia.com> - 2014-01-11 13:08 +0100
  Re: Why do I have to use the keyword this in my Employee example Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-01-11 16:37 +0100
  Re: Why do I have to use the keyword this in my Employee example John Harris <niam@jghnorth.org.uk.invalid> - 2014-01-11 15:58 +0000
    Re: Why do I have to use the keyword this in my Employee example Christoph Michael Becker <cmbecker69@arcor.de> - 2014-01-11 18:02 +0100
      Re: Why do I have to use the keyword this in my Employee example Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-01-11 20:07 +0100
        Re: Why do I have to use the keyword this in my Employee example Christoph Michael Becker <cmbecker69@arcor.de> - 2014-01-12 21:15 +0100
          Re: Why do I have to use the keyword this in my Employee example Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-01-12 21:51 +0100
        Re: Why do I have to use the keyword this in my Employee example John Harris <niam@jghnorth.org.uk.invalid> - 2014-01-14 09:56 +0000
  Re: Why do I have to use the keyword this in my Employee example JJ <duh@nah.meh> - 2014-01-11 23:10 +0700

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