using reduce to count up the number of item in an array

using reduce

//items to count
const votes = [
  'cow',
  'sheep',
  'duck',
  'cow',
  'cow',
  'duck',
  'pig',
  'pig',
  'goat',
  'sheep',
  'pig',
  'cow',
  'goat'
];

//seeting the initial value to an object, this is where the 'key: value' pairs returned from the object will go
const initialValue = {};

//the function takes the tally and the animal and this lives inside the reduce funtion
const reducer = (tally, animal) => {
  //if inside the initial value there is no '!tally[animal]' for the current animal
  if (!tally[animal]) {
    //make one
    tally[animal] = 1;
  } else {
    //if there is 'tally[animal]' for the current animal, add one to it
    tally[animal] = tally[animal] + 1;
  }
  
  //return the tally, thats the object i.e the initial value as it is now
  return tally;
}

const result = votes.reduce(reducer, initialValue);

console.log(result);