e1.js

// E5 - same like E3, but books are in an array now
// 5.1 Use a for loop to decrease the price of all books in the array to half of their original price
// 5.2 Use a for loop to convert all books' authors' last name to lowercase
// .toLower()
// 5.3 Use a for loop to convert all books' authors' last name to uppercase
// .toUpper()
// 5.4 Use a for loop to increase the price of all books written in german by 10 percent

let b1 = {
    title: "Gone with the wind",
    price: 30,
    currency: "EUR"
}

let b2 = {
    title: "The godfather",
    price: 40,
    currency: "USD"
}

// this comes from the database
let books = [b1, b2];