Shuffle object array while preserving keys

Question

i'm working on a project in which i need to shuffle an object array on DOM ready while also preserving keys.

Example:

     var o = [
    {"key_1": {
        "bruce wayne": "batman"
    }},
    {"key_2": {
        "peter parker": "spiderman"
    }},

    {"key_3": {
        "bruce banner": "hulk"
    }}
];

After:

var o = [
    {"key_3": {
        "bruce banner": "hulk"
    }},
    {"key_1": {
        "bruce wayne": "batman"
    }},

    {"key_2": {
        "peter parker": "spiderman"

    }}
];

i've tried doing this a few different ways but haven't been successful. at this point i'm also not sure if this is the best approach for this.

Additional Info: the application has to iterate through the array, showing one key set at a time.

-appreciate any direction,

key_1, key_2 and key_3 are just attributes of the array, here. If you meant an Object, its not possible, as the keys are internally hashed and stored. We cannot the order of their hashes. — thefourtheye
– thefourtheye, Commented Mar 28, 2014 at 15:29
Your arrays have syntax errors. It seems you want objects instead of arrays or, since objects have no order, array of objects. — Oriol
– Oriol, Commented Mar 28, 2014 at 15:32
If you have an array of objects, then you can shuffle the array like any other array. If you have an object, then you can't shuffle its properties because they are not ordered anyway. So, what exactly do you have? — Felix Kling
– Felix Kling, Commented Mar 28, 2014 at 15:34
Despite the syntax error mentioned by Oriol. Do you really need to shuffle the object? Wouldn't it be sufficient to just shuffle an array that contains the keys and use this shuffled array to access the values in the object? — t.niese
– t.niese, Commented Mar 28, 2014 at 15:34
Using "object array" instead of "array" doesn't make your question clearer. Fix your code! — Felix Kling
– Felix Kling, Commented Mar 28, 2014 at 15:36

Community · Accepted Answer · 2017-05-23 12:28:49Z

1

First fix o, it was not correct:

var o = [
    {"key_1": {
        "bruce wayne": "batman"
    }},
    {"key_2": {
        "peter parker": "spiderman"
    }},

    {"key_3": {
        "bruce banner": "hulk"
    }}
];

Now using the shuffle from this answer:

function shuffle(o){ 
    for(var j, x, i = o.length; i; j = Math.floor(Math.random() * i), x = o[--i], o[i] = o[j], o[j] = x);
    return o;
};

You call it like this:

o = shuffle(o);

edited May 23, 2017 at 12:28

CommunityBot

11 silver badge

answered Mar 28, 2014 at 15:35

Raul Guiu

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Community · Accepted Answer · 2017-05-23 10:31:49Z

0

You will need an actual array (instead of an syntax error):

var o = [
    {
        "key": 1,
        "bruce wayne": "batman"
    },
    {
        "key": 2,
        "peter parker": "spiderman"
    },
    {
        "key": 3,
        "bruce banner": "hulk"
    }
]

You can shuffle that easily and the keys are preserved.

edited May 23, 2017 at 10:31

CommunityBot

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answered Mar 28, 2014 at 15:35

Bergi

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Community · Accepted Answer · 2017-05-23 10:31:49Z

0

Your arrays have syntax errors. It seems you want objects instead of arrays or, since objects have no order, array of objects:

var o = [
    {
        "key_1": {"bruce wayne": "batman"}
    },
    {
        "key_2": {"peter parker": "spiderman"}
    },
    {
        "key_3": {"bruce banner": "hulk"}
    }
];
shuffle(o);

Where shuffle is the function defined in this answer or in this one.

Now your array will be something like

[
    {
        "key_3": {"bruce banner": "hulk"}
    },
    {
        "key_2": {"peter parker": "spiderman"}
    },
    {
        "key_1": {"bruce wayne": "batman"}
    }
];

edited May 23, 2017 at 10:31

CommunityBot

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answered Mar 28, 2014 at 15:38

Oriol

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