persons=[
  { name:"Jude", age:30 },
  { name:"Lily", age:25 },
  { name:"Mark", age:34 },
  { name:"Luke", age:18 },
  { name:"John", age:55 },
  { name:"Jack", age:12 }
]
sortedPersons=persons.sort((a, b)=> a.age - b.age)