1) What is the difference between hot and cold Observable? An Observable is cold when data is produced inside the Observable and the Observable is hot when the data is produced outside the Observable. As we just saw the hot Observable is able to share data between multiple subscribers. We call this behaviour “multicasting”.
2) What is typography ? Font, Space, Contrast 3) What is prototype in JavaScript? Old-fashion OOP 4) OOP in JavaScript? ES6: before and after. 5) Comparing JavaScript and TypeScript Old-fashion OOP 6) Review a website. Old-fashion OOP