create multidimensional object from array assigning a value from this array as key in the new object

Question

I have an array like this (each contain more than 2 key-values pairs,I just use 2 for the question)

[{"name":"Joe", "id":17}, {"name":"Bob", "id":17}, {"name":"Carl", "id": 35},{"name":"son", "id": 31},{"name":"smith", "id": 29},{"name":"tom", "id": 35}]

I would like to set a multidimensional object like this. for every DISTINC "id" and inside this "id" contain "id", "name" values .

{
'17' : {
    {"name":"Joe",
    "id":17},
    {"name":"Bob",
    "id":17}
},
'35' : {
    {"name":"Carl", "id": 35},
    {"name":"tom", "id": 35}
},
'31':{"name":"son", "id": 31}
},
 '29':{"name":"smith", "id": 29}
}

As you see I want to assign distinct "id" as key on first object

I think I may misuse brackets, sorry for that, please correct me on this too.

What's your question? How to create the muldimensional object or what's the best way to structured your data? — caballerog
– caballerog, Commented Dec 6, 2015 at 12:07
Why are you storing the id multiple times? Three times for 17 and 35. Seems redundant — Tdelang
– Tdelang, Commented Dec 6, 2015 at 13:02
right @Tdelang. as I said there many other values in the array anyway, consider if were any other . thanks — Mik
– Mik, Commented Dec 6, 2015 at 14:17

Oliver · Accepted Answer · 2015-12-06 12:15:50Z

2

I'd be lazy and use underscore. It has a function called groupBy which does exactly what you need:

_.groupBy(arr, 'id');

JSFiddle.

edited Dec 6, 2015 at 12:15

answered Dec 6, 2015 at 12:05

Oliver

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1 Comment

Mik Over a year ago

this is not lazy since I have to read about underscore but @gre_gor answer is for the concept of the question , even thought I may probably use this

gre_gor · Accepted Answer · 2015-12-06 12:24:19Z

0

Loop over your data and add it to a new object or append it, depending if it already exists.

var data = [{"name":"Joe", "id":17}, {"name":"Bob", "id":17}, {"name":"Carl", "id": 35},{"name":"son", "id": 31},{"name":"smith", "id": 29},{"name":"tom", "id": 35}];

var new_data = {};

for (var i=0; i<data.length; i++)
{
    if (new_data.hasOwnProperty(data[i].id))
        new_data[data[i].id].push(data[i]);
    else
        new_data[data[i].id] = [data[i]];
}
document.getElementById("new_data").textContent = JSON.stringify(new_data, null, 4);

<pre id="new_data"></pre>

answered Dec 6, 2015 at 12:24

gre_gor

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Comments

loxxy · Accepted Answer · 2015-12-06 12:21:37Z

0

Why not just populate a new object?

var obj = {};

var arr = [{"name":"Joe", "id":17}, {"name":"Bob", "id":17}, {"name":"Carl", "id": 35},{"name":"son", "id": 31},{"name":"smith", "id": 29},{"name":"tom", "id": 35}];

arr.forEach(function(k) {
   obj[k.id] = k;
})

answered Dec 6, 2015 at 12:21

loxxy

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