TypeScript uses the class syntactic sugar. Introducing the s2015 with some additions. In this module we'll examine class declarations and inheritance, TypeScripts access modifiers and how they work, using get and set with classes, how abstract classes are implemented, and the use of the static keyword. The vehicle class code on the screen is more or less pure JavaScript. We've added type declarations to the class properties and the function arguments to make it into a TypeScript class. Remember that this is all just syntactic sugar. The constructor method is called when the class instantiated using the new keyword. Functions in the class can be created without using the function keyword or assigning them to this. There's a gotcha with class declarations, they are not hosted in like other declarations in JavaScript. So make sure that they're always at the top of the file. Inheritance works by using the extend keyword. Again, there's nothing particularly TypeScript specific here on the inherited class. Default values can be provided in instructors though. There's another gotcha in this subclass. This will be undefined before you call a super function. So always do this as the first line in a constructor.

Lectures

• Access Modifiers
• Encapsulation Getters & Setters
• Abstracts
• Structural Typing