Find the the most frequent character in a string

getCharacterFrequency.js

const getCharacterFrequency = string => string.split('').reduce((acc, char) => {
  const { length } = string.split(char);

  if (length > acc.frequency) {
    acc.frequency = length;
    acc.mostFrequent = char;
  }

  return acc;
}, { frequency: 0, mostFrequent: '' }).mostFrequent;