Javascript: Group Array of Objects By Property

groupArrayOfObjectsByProperty.js

const groupArrayOfObjectsByProperty = (array, property) => {
    return array.reduce((r, a) => {
        r[a[property]] = [...r[a[property]] || [], a];
        return r;
    }, {});
}

const array = [
  {type: 'dog', name: 'Henry'},
  {type: 'cat', name: 'Steve'},
  {type: 'cat', name: 'Mav'},
  {type: 'monkey', name: 'George'}
];

console.log(groupArrayOfObjectsByProperty(array, "type"))
/*
{
"dog":[{"type":"dog","name":"Henry"}],
"cat":[{"type":"cat","name":"Steve"},{"type":"cat","name":"Mav"}],
"monkey":[{"type":"monkey","name":"George"}]}
*/