const persons = [
  { name: 'lady', age: 24 },
  { name: 'thembeka', age: 34 },
  { name: 'thembeka', age: 37 }
]

const f = person => person.name.length <= 6;
const g = person => person.age ** 2;
const h = person => person.age % 2 === 1;
const i = (ages, person) => [...ages, person.age];

display.log(persons.reduce(i, []))