// one way to have multiple data about a student is with an array

// for each piece of data

var studentNames = [

'Fowad',

'Emil',

'Zoey'

]

var studentAges = [

32,

25,

28

]

console.log(studentNames)

console.log(studentAges)

// Another, more ergonomic way is with objects

var students = [

{ name: 'Fowad', age: 32 },

{ name: 'Emil', age: 25, teacher: true },

{ name: 'Zoey', age: 28 }

]

console.log(students)

// We can access properties with `.`

console.log(students[0].name)

// One object that we have seen before

var Math = {

random: function () {

return 42

},

round: function (x) {

}

}

var person = {

name: 'Emil',

age: 25,

role: 'Teacher',

classes: ['Javascript 1', 'Javascript 2'],

hobbies: {

favourite: 'computers',

sports: 'running to class'

}

}

console.log(person)

// Add new property

person.lastname = 'Bay'

console.log(person)

delete person.lastname

console.log(person)

console.log(person.hobbies.favourite)

console.log({ favourite: 'computers', sports: 'running to class' }.favourite)

'Hello world'.replace('Hello', 'Hej').replace('world', 'verden')

function graduatedClass (student, className) {

if (student.classes.includes(className)) return 'Error'

student.classes.push(className)

}

console.log(person)

graduatedClass(person, 'HTML')

console.log(person)

graduatedClass(person, 'HTML')

var newPerson = {

name: '',

age: ''

}

function addStudent(student) {

if (student.name == null && typeof student.name === 'string') return 'Error'

if (student.age == null) return 'Error'

students.push(student)

}

addStudent({ name: 'Rahim' })

console.log(students)

// ways to access properties

person.name

person['name']

var prop = 'name'

person[prop]

person['name'] = 'Maria'

person[0] = 'Hello world'

console.log(person)

function pick (obj, prop, defaultValue) {

if (obj[prop]) return obj[prop]

return defaultValue

}

pick(person, 'age', 'Unknown')