1

How can I get the most repeated value from an Array in javascript?

This is my array 

var data = [
    { values: "Number of pips" }, 
    { values: 4 }, 
    { values: 4 }, 
    { values: 4 }, 
    { values: 5 }, 
    { values: 2 }, 
    { values: 6 }, 
    { values: 6 },
    { values: 5 }
];

The result should be 4, how can I get this?

I have tried this, taken from Get the element with the highest occurrence in an array

function mode(array)
{
    if(array.length == 0)
        return null;
    var modeMap = {};
    var maxEl = array[0], maxCount = 1;
    for(var i = 0; i < array.length; i++)
    {
        var el = array[i];
        if(modeMap[el] == null)
            modeMap[el] = 1;
        else
            modeMap[el]++;    
        if(modeMap[el] > maxCount)
        {
            maxEl = el;
            maxCount = modeMap[el];
        }
    }
    return maxEl;
}

but this is return 6, not 4.

Community
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3 Answers3

3

The problem with your attempted code is that you do not have an array of numbers, you have an array of objects. If you want to count the most values then you have to use that value, rather than the whole object.

In regards to the code you have attempted, you just need to change the following line:

var el = array[i].values;

Here is the full code:

function mode(array)
{
    if(array.length == 0)
        return null;
    var modeMap = {};
    var maxEl = array[0], maxCount = 1;
    for(var i = 0; i < array.length; i++)
    {
        var el = array[i].values;// This is the change.
        if(modeMap[el] == null)
            modeMap[el] = 1;
        else
            modeMap[el]++;  
        if(modeMap[el] > maxCount)
        {
            maxEl = el;
            maxCount = modeMap[el];
        }
    }
    return maxEl;
}

Here is a working example

musefan
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2

I Got This

var arr= [{ values: "Number of pips" }, { values: 4 }, { values: 4 }, { values: 4 }, { values: 5 }, { values: 2 }, { values: 6 }, { values: 6 }, { values: 5 }];



    var uniqs = {};

    for(var i = 0; i < arr.length; i++) {
        uniqs[arr[i].values] = (uniqs[arr[i].values] || 0) + 1;
    }

    var max = { val: arr[0], count: 1 };
    for(var u in uniqs) {
        if(max.count < uniqs[u]) { max = { val: u, count: uniqs[u] }; }
    }

    alert(max.val);

DEMO

cracker
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-1
  1. Sort the array. (I assume you can do that... else copy it first on another array)
  2. iterate the array and by keeping the previouslyVisited item work this out
Zo72
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    Firstly, don't encourage people to ask questions when they haven't tried to solve the problem themselves. Secondly, your answer doesn't provide a solution. Seriously, you think telling the OP to "work this out" is helpful? I think this would have been better as a comment, then the OP could attempt to code your recommendations – musefan Aug 14 '14 at 09:09
  • @musefan I disagree with your "don't encourage people to ask questions when they haven't tried to solve the problem " I agree my answer could have been a comment. downgrading me was just nasty – Zo72 Aug 14 '14 at 15:50
  • @Zo72: But SO is against people asking question without showing any attempt to solve the problem, it's in the guides. The minimum is to at least include current code... anyway, that's not why you got the downvote. I downvoted because your answer doesn't provide a solution to the problem, it's just a suggestion on how one might be able to solve the problem – musefan Aug 14 '14 at 15:55
  • @musefan given the sketchy question (at the time of my response at least) I gave a sketchy solution. How do I count duplicates in my array ? well sort the array and then iterate over... I thought it was fair... Anyway you had the right to downvote me so I accept that – Zo72 Aug 14 '14 at 20:53