JS associative object with duplicate names

Question

ok, so I have an object like:

var myobject = {
   "field_1": "lorem ipsum",
   "field_2": 1,
   "field_2": 2,
   "field_2": 6
};

as you see there are duplicate names in the object, but with different values. If i go through it like (using jQuery):

$.each(myobject, function(key, value)
{
   console.log(key);
   console.log(myobject[key]);
   console.log(myobject[value]);
}

key - returns the correct key
myobject[key] - returns the name for that key
myobject[value] - returns the last elements', with that name, value

meaning for field_2 it will return 6, though it'll print it 3 times, as it repeats 3 times in the object.

My question is how to obtain the correct value for that duplicate named fields and not just the last one's

Thank you

As far as I know, arrays like this can't work. Where do they come from in the first place? — Pekka
– Pekka, Commented Oct 22, 2010 at 11:01
You have a syntax error in your code - your $.each() function isn't closed.. — kwah
– kwah, Commented Oct 22, 2010 at 12:37

Coin_op · Accepted Answer · 2010-10-22 11:30:27Z

7

That is not an array that is an object. You'd be better creating a property of the object that is an array and store the different values in there.

var myarray = {
   "field_1": "lorem ipsum",
   "field_array": []
};

myarray.field_array.push(value);

then just loop through that property of the array.

edited Oct 22, 2010 at 11:30

answered Oct 22, 2010 at 11:03

Coin_op

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Comments

kwah · Accepted Answer · 2010-10-22 12:58:39Z

Associative arrays do not exist in Javascript - what you have created is an Object using the JSON format.

I suspect that something like this will give you more what you are seeking, though I suggest questioning exactly what it is that you are trying to achieve..

The following code will allow you to access multiple instances of duplicated 'keys', but is

var myDataset = [
   { "field_1": "lorem ipsum" },
   { "field_2": 1 },
   { "field_2": 2 },
   { "field_2": 6 }
];


$.each(myDataset, function(valuePairIndex, value)
{
    $.each(myDataset[valuePairIndex], function(key, value1)
    {
       var valuePair = myDataset[valuePairIndex];
       console.log(valuePairIndex);
       console.log(key + ' = ' + valuePair[key]);

//       console.log('key = ' + key);
//       console.log('valuePair[key] = ' + valuePair[key]);
    });
});

gblazex · Accepted Answer · 2010-10-22 11:08:16Z

3

Your code has invalid syntax.
There are no assocative arrays in Javascript
The thing you defined is an Object
If you give value to a property 3 times, sure it will contain the last value

Test

var obj = {
   "field_1": "lorem ipsum",
   "field_2": 1,
   "field_2": 2,
   "field_2": 6
};

for ( var i in obj ) {
  console.log(i + " = " + obj[i]);
}

OUTPUT

field_1 = lorem ipsum
field_2 = 6

answered Oct 22, 2010 at 11:08

gblazex

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Comments

Bal · Accepted Answer · 2010-10-22 11:02:46Z

2

The keys must be unique.

answered Oct 22, 2010 at 11:02

Bal

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Comments

Spudley · Accepted Answer · 2010-10-22 11:08:56Z

2

You can't do this. The array key must be unique.

If you've got Firefox/Firebug installed (or similar in another browser), you can try it by entering this into the Firebug console:

var myarray = {
   "field_1": "lorem ipsum",
   "field_2": 1,
   "field_2": 2,
   "field_2": 6
};
console.dir(myarray);

Firebug will respond with:

field_1      "lorum ipsum"
field_2      6

in other words, it works, but each subsequent value specified for field_2 overwrites the previous one; you can only have one value for it at a time.

The closest you can get to what you want is to make field_2 an array in itself, something like this:

var myarray = {
   "field_1": "lorem ipsum",
   "field_2": [1,2,6]
};

If you do console.log now, you'll get this:

field_1      "lorum ipsum"
field_2
    0        1
    1        2
    2        6

Hope that helps.

answered Oct 22, 2010 at 11:08

Spudley

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3 Comments

Pointy Over a year ago

Those are not arrays, they're objects. You can call them "myarray" if you like, of course, but they're not arrays.

Spudley Over a year ago

@Pointy - you're right of course. I used the word 'array' because that's how it was asked in the question.

Pointy Over a year ago

Sorry to have worded that so rudely; I had just hurt my foot on a chair in this dark room before clicking into this question :-)

David Mårtensson · Accepted Answer · 2010-10-22 11:10:12Z

2

It is not possible.

The resulting object does only contain 2 elements, the first and second field_2 elements are lost on creation.

answered Oct 22, 2010 at 11:10

David Mårtensson

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Comments

Alex · Accepted Answer · 2010-10-22 11:05:29Z

1

The only way to get around it would be to either change the fields to unique identifiers, or something like:

var myarray = {
   "field_1": "lorem ipsum",
   "field_2": [
       {"value_1": 1},
       {"value_2": 2},
       {"value_3": 6}
   ]
};

answered Oct 22, 2010 at 11:05

Alex

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Comments

David Hedlund · Accepted Answer · 2010-10-22 11:06:54Z

0

You're overwriting the same value several times.

What you want is probably something like:

var myarray = {
   "field_1": "lorem ipsum",
   "field_2": [1,2,6]
};

Which could be written in a manner similar to what you currently have:

var myarray = {};

myarray.field_1 = [];
myarray.field_1.push('lorem ipsum');
myarray.field_2 = [];
myarray.field_2.push(1);
myarray.field_2.push(2);
myarray.field_2.push(6);

Note that I made field_1 an array as well, which - for consistency - I thought you might want.

answered Oct 22, 2010 at 11:06

David Hedlund

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1 Comment

Cory Gross Over a year ago

The top definition of myarray is not the same as the definition of myarray below. You should either place the string "lorem ipsum" in an array literal in field_1 of the first definition, or simply assign the string "lorem ipsum" to field_1 in the second definition.

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