davidystephenson

/*
// 1. Write a JavaScript expression to calculate the sum of two numbers, `num1` and `num2`.
var num1 = 10
var num2 = 11
var sum = num1 + num2
console.log(sum)

// 2. Write a program to calculate the area of a rectangle given its length and width.
var length = 5
var width = 10

davidystephenson

/*
// 1. Declare a variable called `personName` and assign your name to it.
var personName = 'David Y. Stephenson'
console.log(personName)

// 2. Create a variable `age` and assign your age to it.
var age = 34
console.log(age)

// 3. Create a variable `isStudent` and assign it a boolean value.

davidystephenson

/*
var x = 8 - 1
console.log('x', x)
var y = 2 + 6
console.log('y', y)
var equal = x === y
console.log('equal', equal)
var notEqual = x !== y
console.log('notEqual', notEqual)
var greater = x > y

davidystephenson

/*
var message = 'hello'

var guestList = ['Zelda', 'Dorothy', 'Tallulah', 1, true, { x: 1 }, ['a', 1, false]]
var zeldaDetails = {
  first: 'Zelda',
  'last': 'Fitzgerald',
  occupation: 'Writer'
}

davidystephenson

interface Tree {
  branches: number
  species: string
}
interface Vehicle {
  position: number
  speed: number
}
interface Animal {
  legs: number

davidystephenson

type Input <T> = string | number | T

const input1: Input<boolean> = true
const input2: Input<string[]> = true 

type Collection <T> = [T, T, T]

const stringCollection: Collection<string> = ['a', 'b', 'c']
const numberCollection: Collection<number> = ['a', 2, 3]

davidystephenson

type Input = string[] | number[]

interface Tree {
  branches: number
  species: string
  height: number
  rings: number
}

interface WildTree extends Tree {

davidystephenson

type Input <T> = string | number | T

const i: Input<boolean> = false

const x: Input<number[]> = [1, 2, 3]

interface Guest {
  name: string
  email: string
  age: number

davidystephenson

interface Person {
  name: string
  age: number
  email: string
  phone: string
}
interface SpecialPerson extends Person {
  reason: string
}
const tallulah: SpecialPerson = {

davidystephenson

interface Guest {
  name: string
  age: number
  email: string
  phone: string
  address: string
}
type GuestKey = keyof Guest // 'name' | 'age' | 'email' | 'phone' | 'address'

const dorothy = {