Javascript Dynamic Arrays and Object

Question

Is this possible?

So I need to have an array with a dynamic name and content what can be extended and accessed.

object = {};
var two = ['thing', 'thing2'];
for(one in two){
    object[two[one]] = [];
}

If yes but not in this way, then how?

Eh? I'm not sure what you're asking. Also, iterating an Array with for-in is considered bad practice; use a C-style for loop or use Array.prototype.forEach if available. — strager
– strager, Commented Nov 23, 2010 at 21:11
Note that the code sample you show there declares a global one variable, unless you have var one elsewhere in your function. Best practice for iterating properties of an object is for (var prop in obj){ if (obj.hasOwnProperty(prop)){ ... } }. — Phrogz
– Phrogz, Commented Nov 23, 2010 at 21:15

Jacob Relkin · Accepted Answer · 2010-11-23 21:12:45Z

1

This is definitely doable, just make sure that the object owns the property and it's not inherited from higher up in the prototype chain:

object = {};
var two = ['thing', 'thing2'];

for..in:

for(var one in two){
    if(two.hasOwnProperty(one))
       object[two[one]] = [];
}

for:

for(var i = 0; i < two.length; i++)
   object[two[i]] = [];

answered Nov 23, 2010 at 21:12

Jacob Relkin

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2 Comments

You are missing a var on one, causing it to be globally defined (and potentially collide).

@Phrogz, Oops. Missed that one. Thanks!

Phrogz · Accepted Answer · 2010-11-23 21:17:11Z

1

var object = {};
var props  = 'thing thing2'.split(' ');
for (var i=0,len=props.length;i<len;++i){
  object[props[i]] = [];
}

answered Nov 23, 2010 at 21:17

Phrogz

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