Most frequent element in array
JavaScript, Array · Sep 15, 2020
Returns the most frequent element in an array.
- Use
Array.prototype.reduce()to map unique values to an object's keys, adding to existing keys every time the same value is encountered. - Use
Object.entries()on the result in combination withArray.prototype.reduce()to get the most frequent value in the array.
const mostFrequent = arr =>
Object.entries(
arr.reduce((a, v) => {
a[v] = a[v] ? a[v] + 1 : 1;
return a;
}, {})
).reduce((a, v) => (v[1] >= a[1] ? v : a), [null, 0])[0];mostFrequent(['a', 'b', 'a', 'c', 'a', 'a', 'b']); // 'a'
