Get the element with the highest occurrence in an array

Question

I\'m looking for an elegant way of determining which element has the highest occurrence (mode) in a JavaScript array.

For example, in

[\'pear\', \'a         


        

Answer 1

With ES6, you can chain the method like this:

    function findMostFrequent(arr) {
      return arr
        .reduce((acc, cur, ind, arr) => {
          if (arr.indexOf(cur) === ind) {
            return [...acc, [cur, 1]];
          } else {
            acc[acc.indexOf(acc.find(e => e[0] === cur))] = [
              cur,
              acc[acc.indexOf(acc.find(e => e[0] === cur))][1] + 1
            ];
            return acc;
          }
        }, [])
        .sort((a, b) => b[1] - a[1])
        .filter((cur, ind, arr) => cur[1] === arr[0][1])
        .map(cur => cur[0]);
    }
    
    console.log(findMostFrequent(['pear', 'apple', 'orange', 'apple']));
    console.log(findMostFrequent(['pear', 'apple', 'orange', 'apple', 'pear']));

If two elements have the same occurrence, it will return both of them. And it works with any type of element.