Answers for "array of objects grouped by unique values"

get unique values from array of objects javascript

const data = [
  { group: 'A', name: 'SD' }, 
  { group: 'B', name: 'FI' }, 
  { group: 'A', name: 'MM' },
  { group: 'B', name: 'CO'}
];
const unique = [...new Set(data.map(item => item.group))]; // [ 'A', 'B']

create unique set of array of objects

function unique(array, propertyName) {
   return array.filter((e, i) => array.findIndex(a => a[propertyName] === e[propertyName]) === i);
}