Array of People

people.js

const people = [
    { firstName: 'Sam', lastName: 'Hughes', DOB: '07/07/1978', department: 'Development', salary: '45000' },
    { firstName: 'Terri', lastName: 'Bishop', DOB: '02/04/1989', department: 'Development', salary: '35000' },
    { firstName: 'Jar', lastName: 'Burke', DOB: '11/01/1985', department: 'Marketing', salary: '38000' },
    { firstName: 'Julio', lastName: 'Miller', DOB: '12/07/1991', department: 'Sales', salary: '40000' },
    { firstName: 'Chester', lastName: 'Flores', DOB: '03/15/1988', department: 'Development', salary: '41000' },
    { firstName: 'Madison', lastName: 'Marshall', DOB: '09/22/1980', department: 'Sales', salary: '32000' },
    { firstName: 'Ava', lastName: 'Pena', DOB: '11/02/1986', department: 'Development', salary: '38000' },
    { firstName: 'Gabriella', lastName: 'Steward', DOB: '08/26/1994', department: 'Marketing', salary: '46000' },
    { firstName: 'Charles', lastName: 'Campbell', DOB: '09/04/1977', department: 'Sales', salary: '42000' },
    { firstName: 'Tiffany', lastName: 'Lambert', DOB: '05/11/1990', department: 'Development', salary: '34000' },
    { firstName: 'Antonio', lastName: 'Gonzalez', DOB: '03/24/1985', department: 'Office Management', salary: '49000' },
    { firstName: 'Aaron', lastName: 'Garrett', DOB: '09/04/1985', department: 'Development', salary: '39000' },
];

// Exercises

// 1) What is the average income of all the people in the array?


// 2) Who are the people that are currently older than 30?


// 3) Get a list of the people's full name (firstName and lastName).


// 4) Get a list of people in the array ordered from youngest to oldest.


// 5) How many people are there in each department?

for question 2
const olderThirty = (p = people) => {
const currentDate = new Date();
const thirtyYearsAgo = currentDate.getFullYear() - 30;

let a = p.filter((person) => {
    const dob = new Date(person.DOB);
    const dobYear = dob.getFullYear();
    const dobMonth = dob.getMonth() + 1;
    const dobDay = dob.getDate();
    return (dobYear < thirtyYearsAgo) || (dobYear === thirtyYearsAgo && dobMonth < currentDate.getMonth() + 1) || (dobYear === thirtyYearsAgo && dobMonth === currentDate.getMonth() + 1 && dobDay <= currentDate.getDate());
});
return a;

};
console.log(olderThirty());