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Re: Comparing some of the ways to create objects

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John Harris wrote:

> It's time to compare ways of creating objects now that the full release
> version of Firefox implements class declarations. The code below shows
> three of the ways. They are all ones where an object is created by using
> new and a constructor. 

I don't see why that is so special.  I will add several more suggestions 
below that use three different object creation APIs, including a 'new-and-
constructor' version.  Two of them also share the same sort of prototype-
based object mechanism shared by your three samples.

>                        These ways are more suited to cases where several
> objects of the same kind are to be created, or where the code might be
> reused in other projects. Several other ways exist but they are more
> suited to the ad hoc creation of only one object.

I believe all three techniques I suggest below are similarly suited to 
the creation of several objects of the same kind.  The second one 
(`thing5`) is more memory-intensive, and probably is not suitable for 
hundreds of thousands or millions of instances of the type, but other 
than that, they have similar characteristics.  `thing5` does offer the 
ability to have truly private implementation details, which many other 
techniques really don't.

> The three examples illustrate :
>   1  Class-style creation : Using an ES6 class declaration;
>   2  Class-style creation : Using ES3 features;
>   3  Prototypal-style creation : Using ES3 features.

These three also illustrate standard prototypal creation, regardless of 
whether some syntactic sugar has been added to help make them seem more 
similar to C++-style OOP classes.

> [ ... code elided ... ]

My techniques follow.  I'm wondering if you see these ones as somehow 
lesser techniques than the three you present.  And if so, why is that?

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
 
   function Thing4(phrase) {
      var count = 0;
      this.toString = function() {return phrase;}
      this.incr = function() {count++;}
      Object.defineProperties(this, {text: {
        get: function() {return phrase;}
      }, count: {
        get: function() {return count;}
      }})
    } // Thing4

    var a4 = new Thing4("Hello from Thing4 a4");
    a4 + ': ' + a4.count; //=> "Hello from Thing4 a4: 0"
    a4.incr();
    a4 + ': ' + a4.count; //=> "Hello from Thing4 a4: 1"
    var b4 = new Thing4("Hello from Thing4 b4");
    b4 + ': ' + b4.count; //=> "Hello from Thing4 b4: 0"

    function thing5(phrase) {
      var count = 0;
      return {
        toString: function() {return phrase;},
        incr: function() {count++},
        get count() {return count;}
      };
    } // thing5

    var a5 = thing5("Hello from thing5 a5");
    a5 + ': ' + a5.count; //=> "Hello from thing5 a5: 0"
    a5.incr();
    a5 + ': ' + a5.count; //=> "Hello from thing5 a5: 1"
    var b5 = thing5("Hello from thing5 b5");
    b5 + ': ' + b5.count; //=> "Hello from thing5 b5: 0"


    var Thing6 = {
      init: function(phrase) {
        this.text = phrase;
        this.count = 0;
      },
      incr: function() {
        this.count++;
      },
      toString: function() {
        return this.text ;
      }
    }; // Thing6

    var a6 = Object.create(Thing6);
    a6.init("Hello from Thing6 a6");
    a6 + ': ' + a6.count; //=> "Hello from Thing6 a6: 0"
    a6.incr();
    a6 + ': ' + a6.count; //=> "Hello from Thing6 a6: 1"
    var b6 = Object.create(Thing6);
    b6.init("Hello from Thing6 b6");
    b6 + ': ' + b6.count; //=> "Hello from Thing6 b6: 0"

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

Cheers,

  -- Scott  

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Thread

Comparing some of the ways to create objects John Harris <niam@jghnorth.org.uk.invalid> - 2016-04-03 16:09 +0100
  Re: Comparing some of the ways to create objects Scott Sauyet <scott@sauyet.com> - 2016-04-04 04:15 +0000
    Re: Comparing some of the ways to create objects Stefan Weiss <krewecherl@gmail.com> - 2016-04-04 15:20 +0200
      Re: Comparing some of the ways to create objects Scott Sauyet <scott@sauyet.com> - 2016-04-05 04:04 +0000
    Re: Comparing some of the ways to create objects John Harris <niam@jghnorth.org.uk.invalid> - 2016-04-04 16:48 +0100
      Re: Comparing some of the ways to create objects Scott Sauyet <scott@sauyet.com> - 2016-04-05 04:04 +0000
        Re: Comparing some of the ways to create objects John Harris <niam@jghnorth.org.uk.invalid> - 2016-04-07 15:07 +0100
          Re: Comparing some of the ways to create objects Scott Sauyet <scott@sauyet.com> - 2016-04-08 01:10 +0000
            Re: Comparing some of the ways to create objects John Harris <niam@jghnorth.org.uk.invalid> - 2016-04-08 14:55 +0100
    Re: Comparing some of the ways to create objects Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-04-04 22:12 +0200
      Re: Comparing some of the ways to create objects John Harris <niam@jghnorth.org.uk.invalid> - 2016-04-05 09:57 +0100
    Re: Comparing some of the ways to create objects John Harris <niam@jghnorth.org.uk.invalid> - 2016-04-06 16:41 +0100
      Re: Comparing some of the ways to create objects Scott Sauyet <scott@sauyet.com> - 2016-04-06 23:42 +0000
        Re: Comparing some of the ways to create objects John Harris <niam@jghnorth.org.uk.invalid> - 2016-04-07 16:09 +0100
          Re: Comparing some of the ways to create objects Scott Sauyet <scott@sauyet.com> - 2016-04-08 02:05 +0000
            Re: Comparing some of the ways to create objects John Harris <niam@jghnorth.org.uk.invalid> - 2016-04-08 15:43 +0100
              Re: Comparing some of the ways to create objects Scott Sauyet <scott@sauyet.com> - 2016-04-09 00:01 +0000
                Re: Comparing some of the ways to create objects Scott Sauyet <scott@sauyet.com> - 2016-04-09 16:46 +0000
                Re: Comparing some of the ways to create objects Scott Sauyet <scott@sauyet.com> - 2016-04-10 16:51 +0000
                Re: Comparing some of the ways to create objects Stanimir Stamenkov <s7an10@netscape.net> - 2016-05-08 17:27 +0300
                Re: Comparing some of the ways to create objects John Harris <niam@jghnorth.org.uk.invalid> - 2016-04-10 11:31 +0100
                Re: Comparing some of the ways to create objects John Harris <niam@jghnorth.org.uk.invalid> - 2016-04-10 11:52 +0100

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