sort

sort.js

var employees = [new Employee("e1", 28), new Employee("e2", 31), new Employee("e3", 25)]

function Employee(name, age) {
  this.name = name
  this.age = age
}

function sort(employees) {
  if (employees == null || employees.length == 0) {
      return employees
  }
  //copy the array to avoid side effect and hence maintain "sort" as a pure function
  return employees.slice(0).sort(function(lhs, rhs) {
  	return lhs.age - rhs.age
  })
}

console.log(sort(employees))