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Groups > comp.lang.javascript > #34598

Re: Get the object structure correct.

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Den fredag 19 januari 2018 kl. 04:56:09 UTC+1 skrev Thomas 'PointedEars' Lahn:
> Michael Haufe (TNO) wrote:
> 
> > Jonas Thörnvall wrote:
> >> var People = [
> >>     {Name: "Name", Surname: "Surname"},
> >>     {Name:"AAA", Surname:"ZZZ"},
> >>     {Name: "Name", Surname: "AAA"}
> >> ];
> >> I guess people is an array holding three indexes above?
> >> The properties of people is Name and Surname
> > 
> > JavaScript developers have a tendency to "golf" [1] their code just like
> > Perl programmers. Which can make things unnecessarily terse.
> 
> But often also less error-prone.  YMMV.
>  
> > I would have wrote the example like this:
> > 
> > </script>
> > class Person {
> >     constructor(name, surName) {
> >         this.name = name;
> >         this.surName = surName
> >     }
> > }
> > 
> > var people = [
> >     new Person(Brendan", "Eich"),
> >     new Person("Alan","Kay"),
> >     new Person("Robert", "Carlyle")
> > ]
> 
> Names starting with a capital letter should be reserved for constructors, 
> classes and constants  That is, “People”, “Name”, and “Surname” should all 
> be lowercase here.
> 
> Using the same pattern as you used for “tracks”, one can set up the data and 
> have the custom instances without repeating oneself (ES 2015+):
> 
>   people = people.map((obj) => new Person(obj.name, obj.surname));
> 
> or, more backwards-compatible (ES Ed. 5+):
> 
>   people = people.map(function (obj) {
>     return new Person(obj.name, obj.surname);
>   });
> 
> Or, most backwards-compatible (all):
> 
>   for (var i = people.length; i--;)
>   {
>     var obj = people[i];
>     people[i] = new Person(obj.name, obj.surname);
>   };
> 
> If the class/type has a default constructor (and this is one example that 
> show that it is a good idea to have one), and provides means to set 
> individual properties, then this can be even simpler.  For example:
> 
>   people = people.map((obj) => {
>     var person = new Person();
>     Object.assign(person, obj);
>   });
> 
> It is also a good idea to have a constructor that in addition to positional 
> arguments accepts an initializer object as first and only argument.
> 
>   people = people.map((obj) => new Person(obj));
> 
> Such a constructor is particularly useful with JSON.parse(json, reviver), 
> and in general it is a good idea if a constructor can be called as a 
> function for type conversion (like type casting).  But apparently this is 
> not possible with ECMAScript classes:
> 
>   class Person
>   {
>     constructor (...args)
>     {
>       if (!(this instanceof Person)) return new Person(...args);
> 
>       /* initialize */
>     }
>   }
> 
>   /* TypeError: Class constructor Person cannot be invoked without 'new' */
>   Person()
> 
> This works:
> 
>   function Person (...args)
>   {
>     /* 
>      * For backwards compatibility JSX:object.js introduces 
>      * Function.prototype.construct(), and I am also thinking about
>      * adding Function.prototype.toFactory() for DRY.
>      */
>     if (!(this instanceof Person)) return new Person(...args);
> 
>     /* initialize */
>   }
> 
>   /* > Person {} */
>   Person()
> 
> BTW, one should have read <http://www.kalzumeus.com/2010/06/17/falsehoods-programmers-believe-about-names/>.
> 
> -- 
> PointedEars
> FAQ: <http://PointedEars.de/faq> | <http://PointedEars.de/es-matrix>
> <https://github.com/PointedEars> | <http://PointedEars.de/wsvn/>
> Twitter: @PointedEars2 | Please do not cc me./Bitte keine Kopien per E-Mail.

I like the old version Thomas 
  for (var i = people.length; i--;) 
  { 
    var obj = people[i]; 
    people[i] = new Person(obj.name, obj.surname); 
  }; 

But if Person was initself a property of adress would i then write as below
to create a new person object on the adress. It is the syntax that escapes me.

  for (var i = people.length; i--;) 
  { 
    var obj = people[i]; 
    residence[x].people[i] = new Person(obj.name, obj.surname); 
  };

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Thread

Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-18 02:50 -0800
  Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-18 03:03 -0800
  Re: Get the object structure correct. "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2018-01-18 14:39 -0800
    Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-18 16:38 -0800
      Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-18 16:56 -0800
        Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-18 17:19 -0800
          Re: Get the object structure correct. "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2018-01-18 17:33 -0800
            Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-18 19:54 -0800
            Re: Get the object structure correct. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-01-19 04:55 +0100
              Re: Get the object structure correct. "Mark-" <nospam@mapson.xyz> - 2018-01-19 04:03 +0000
              Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-18 20:06 -0800
                Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-18 20:30 -0800
                Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-18 20:49 -0800
                Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-19 00:12 -0800
                Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-19 02:01 -0800
                Re: Get the object structure correct. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-01-25 07:49 +0100
                Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-30 01:06 -0800
                Re: Get the object structure correct. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-01-30 11:01 +0100
                Re: Get the object structure correct. "Mark-" <nospam@mapson.xyz> - 2018-01-30 13:37 +0000
                Re: Get the object structure correct. John G Harris <niam@jghnorth.org.uk.invalid> - 2018-01-30 19:14 +0000
      Re: Get the object structure correct. "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2018-01-18 17:24 -0800
        Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-18 17:41 -0800
          Re: Get the object structure correct. "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2018-01-18 17:47 -0800
            Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-18 18:29 -0800
              Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-18 18:46 -0800
                Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-18 18:54 -0800
                Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-18 19:00 -0800
        Re: Get the object structure correct. John G Harris <niam@jghnorth.org.uk.invalid> - 2018-01-19 11:20 +0000
          Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-19 11:48 -0800
            Re: Get the object structure correct. John G Harris <niam@jghnorth.org.uk.invalid> - 2018-01-19 20:03 +0000
              Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-19 12:18 -0800
              Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-19 12:48 -0800
                Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-19 13:02 -0800
                Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-20 18:07 -0800
                Re: Get the object structure correct. Jonas Thörnvall <jonas.thornvall@gmail.com> - 2018-01-21 00:55 -0800

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