What Is a Class?
By the end of this lesson, you'll be able to:
- Define what a class is: a blueprint for creating objects
- Distinguish between a class definition and an instance of that class
- Recognize that every Apex file you've written so far has actually been inside a class
Prerequisites: Module 9: "Methods: Reusable Instructions"
A blueprint, not the thing itself
public class GymMember {
public String name;
public Integer age;
}GymMember doesn't represent any specific member — it's a template describing what data every gym member has: a name and an age. No actual member exists yet; this is just the shape.
A real-world analogy: architectural blueprints
An architect's blueprint for a house describes where the walls, doors, and windows go — but a blueprint is not a house you can live in. Many actual houses can be built from the same blueprint, each standing separately. A class works the same way: one blueprint, many actual objects built from it.
You've been inside a class all along
Every System.debug and every method from Modules 1-9 has technically lived inside a class already — the seeder and lesson code you've been reading is itself organized into classes. This module makes that structure explicit and puts it in your hands.
Exercise
As a comment, explain the difference between a class and an object in your own words.
Show hint
A class is the blueprint; an object is one specific thing built from it.
What Is a Class? Quiz
My Notes
Log in to keep private notes on this lesson.
Questions about this lesson
No questions yet — be the first to ask.
Log in to ask a question about this lesson.
Summary
A class is a blueprint that describes what data and behavior a certain kind of "thing" has — every object you create in Apex is built from a class.