Lesson 2.3Lesson 9 of 24
Classes and inheritance
Given a business requirement, apply fundamentals of class implementation to solve the business requirement.
Key points
- 1A class is a function. Methods go on its prototype and are shared; fields are created on each instance.
- 2Static members belong to the class itself. Instances do not have them, but subclasses inherit them.
- 3Private fields start with #, can be read only inside the class body, and are not normal string keys.
- 4A derived constructor must call super() before it uses this. super.method() calls the parent version.
- 5Class declarations are not usable before their line, and class bodies always run in strict mode.
What the exam guide checks here
Objective wording from the exam guide (English).
- 2.3.K1class syntax: constructor, methods, static members, getters and setters, private fields
- 2.3.K2Inheritance with extends and super; classes as syntax over prototypes
- 2.3.S1Choose the class code that meets a requirement
Lock it in
Answer scenario questions on this topic. Every option comes with an explanation.
Practise 2.3 · 12 questions