javascript map return array with distinc values

1//ES6
2let array = [
3  { "name": "Joe", "age": 17 },
4  { "name": "Bob", "age": 17 },
5  { "name": "Carl", "age": 35 }
6];
7array.map(item => item.age)
8  .filter((value, index, self) => self.indexOf(value) === index)
9
10> [17, 35]

1const unique = [...new Set(array.map(item => item.age))];