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

Solution 1

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.

Solution 2

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]);
    });
});

Solution 3

1. Your code has invalid syntax.
2. There are no assocative arrays in Javascript
3. The thing you defined is an Object
4. 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

Solution 4

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.

Solution 5

The keys must be unique.

View more solutions

Comments

[Pointy]

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

[Spudley]

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

[Pointy]

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 :-)

[Cory Gross]

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.