JSFiddle - React, Tailwind, and code Playground

JavaScript

_personsList = [{"name":"Joe", "age":17}, 
        			 {"name":"Bob", "age":17}, 
        			 {"name":"Carl", "age": 35}];

_uniqAgeList = _.groupBy(_personsList,"age");
_uniqAges = Object.keys(_uniqAgeList);

document.body.innerHTML=_uniqAges;