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']//ES6
let array = [
{ "name": "Joe", "age": 17 },
{ "name": "Bob", "age": 17 },
{ "name": "Carl", "age": 35 }
];
array.map(item => item.age)
.filter((value, index, self) => self.indexOf(value) === index)
> [17, 35]const categories = ['General', 'Exotic', 'Extreme', 'Extreme', 'General' ,'Water', 'Extreme']
.filter((value, index, categoryArray) => categoryArray.indexOf(value) === index);
This will return an array that has the unique category names
['General', 'Exotic', 'Extreme', 'Water']