sortUsersByAge.js

var users = [
        {
            "age": 99.0,
            "name": "Saly"
        }, {
            "age": 121,
            "name": "Rob"
        }, {
            "age": 0.3,
            "name": "Tomek"
        }, {
            "age": 15.34,
            "name": "Joy"
        }, {
            "age": 5.5,
            "name": "Sam"
        }];

    function sortUsersByAge(usersArray) {
        return usersArray.sort(function (a, b) {
            return parseFloat(a.age) - parseFloat(b.age);
        });
    }