Question

I have an array with repeating values:

[0, 1, 6, 0, 1, 0]

What is an efficient way to return the highest amount that a specific value repeats?

In the example array I would want the script to return 3 because the number 0 repeats the most often and it repeats 3 times.
I’m already using jQuery and Underscore.

Answer 1

This is similar to the basic approach, but utilizes underscore’s reduce and max functions. If you had a really really really large array, I hope it’s clear how you could parallelize this with a map phase before the reduce.

var arr = [1,0,2,3,4,0,3,0];
var counts = _.reduce(arr, function(counts, val) {
    if (counts[val]) {
        counts[val]++;
    } else {
        counts[val] = 1;
    }
    return counts;
}, {});
return _.max(counts);