Javascript: best way to instantiate an array of objects

Question

What is the easiest was to populate an array with a large number of objects created with a constructor?

I have a constructor function than makes TV and movie objects:

function Media(name, boxCover) {
    this.name = name;
    this.boxCover = boxCover;
};

I am making many objects that I want to put into an array. This does not work:

var table = [
var avengers = new Media("avengers",'../assets/boxcovers/avengers.jpg');
var blade_runner = new Media("blade_runner",'../assets/boxcovers/blade_runner.jpg');
var brave = new Media("brave",'../assets/boxcovers/brave.jpg');
var catching_fire = new Media("catching_fire",'../assets/boxcovers/catching_fire.jpg');
var django = new Media("django",'../assets/boxcovers/django.jpg');
var finding_nemo = new Media("finding_nemo",'../assets/boxcovers/finding_nemo.jpg');
];

I also tried putting table.push( at the beginning of each line. Do I really need to list each object again in the array like this or I can save the duplicate effort:

table = [avengers, blade_runner, etc.

You have to separate the variable declarations and array initialiser, you can't do both in one statement. — RobG
– RobG, Commented Jul 5, 2015 at 23:33

Jan · Accepted Answer · 2015-07-05 23:31:39Z

5

The syntax for this would be

var table = {
    mykey: myproperty,
    mykey2: myproperty2
};

If you want your variable to be an object, that is you can access properties by calling f.e table.avengers, your declaration should look like:

var table = {
    avengers: new Media("avengers",'../assets/boxcovers/avengers.jpg'),
    blade_runner: new Media("blade_runner",'../assets/boxcovers/blade_runner.jpg'),
    brave: new Media("brave",'../assets/boxcovers/brave.jpg')
    //... and so on and so forth
};

If you only want to be able to loop through them, you can create it as an array:

var table = [
    new Media("avengers",'../assets/boxcovers/avengers.jpg'),
    new Media("blade_runner",'../assets/boxcovers/blade_runner.jpg'),
    new Media("brave",'../assets/boxcovers/brave.jpg')
    //... and so on and so forth
];

edited Jul 5, 2015 at 23:31

answered Jul 5, 2015 at 23:26

Jan

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Comments

Gurpreet Singh · Accepted Answer · 2015-07-05 23:34:34Z

1

You are using wrong syntax. Try this instead:

function Media(name, boxCover) {
    this.name = name;
    this.boxCover = boxCover;
};

var table = [
 new Media('avengers','../assets/boxcovers/avengers.jpg'),
 new Media('blade_runner','../assets/boxcovers/blade_runner.jpg')         
];

edited Jul 5, 2015 at 23:34

answered Jul 5, 2015 at 23:28

Gurpreet Singh

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Comments

Mark Schultheiss · Accepted Answer · 2015-07-05 23:35:01Z

0

You can use a simple syntax also such as:

var mediatable = [];
var entry = {
    name: {},
    boxCover: {}
};
mediatable.push({
    name: "avengers",
    boxCover: '../assets/boxcovers/avengers.jpg'
});
mediatable.push({
    name: "blade_runner",
    boxCover: '../assets/boxcovers/blade_runner.jpg'
});
alert(mediatable.length);

or push it using the object:

entry.name = "brave";
entry.boxCover = '../assets/boxcovers/brave.jpg';
mediatable.push(entry);
alert(mediatable.length + ":" + mediatable[1].name);

answered Jul 5, 2015 at 23:35

Mark Schultheiss

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Comments

Mehdi · Accepted Answer · 2015-07-06 00:10:54Z

0

function Media(name, boxCover) {
    this.name = name;
    this.boxCover = boxCover;
};

function MediaTable(data) {
    var table = {};
    data.forEach(function(el){
        table[el[0]] = new Media(el[0], el[1])
    })

    return table;
};

var tableData = [
        ["avengers", '../assets/boxcovers/avengers.jpg'],
        ["blade_runner", '../assets/boxcovers/blade_runner.jpg'],
        ["brave" , '../assets/boxcovers/brave.jpg'],
        ["catching_fire", '../assets/boxcovers/catching_fire.jpg'],
        ["django", '../assets/boxcovers/django.jpg'],
        ["finding_nemo", '../assets/boxcovers/finding_nemo.jpg']
    ],
    table = new MediaTable(tableData);

answered Jul 6, 2015 at 0:10

Mehdi

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Comments

marizikmund · Accepted Answer · 2015-07-05 23:31:30Z

-1

Rewrite your var table like this, that's all needed:

var table = [
  new Media("avengers",'../assets/boxcovers/avengers.jpg'),
  new Media("blade_runner",'../assets/boxcovers/blade_runner.jpg'),
  new Media("brave",'../assets/boxcovers/brave.jpg'),
  new Media("catching_fire",'../assets/boxcovers/catching_fire.jpg'),
  new Media("django",'../assets/boxcovers/django.jpg'),
  new Media("finding_nemo",'../assets/boxcovers/finding_nemo.jpg')
];

answered Jul 5, 2015 at 23:31

marizikmund

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