Classes

Learning TypeScript's Classes chapter introduces a plethora of type system features and syntaxes around classes:

• Declaring and using class methods and properties
• Marking properties readonly and/or optional
• Using class names as types in type annotations
• Implementing interfaces to enforce class instance shapes
• Extending classes, along with assignability and override rules for subclasses
• Marking classes and methods as abstract
• Adding type system modifiers to class fields