Understanding Classes in Salesforce Apex

Classes are essentially blueprints for creating objects. They encapsulate data and methods (functions) to perform operations on that data. Classes in Apex are similar to classes in other object-oriented programming languages like Java or C#.

Syntax

A class in Apex is defined using the class keyword followed by the class name and optional access modifiers (public, private, or global). Here's a basic syntax:

public class MyClass {
    // Class members (variables and methods) go here
}

Access Modifiers

public: Accessible from any Apex code within the same application.
private: Accessible only within the same class.
global: Accessible from any Apex code in the Salesforce organization.

Class Members

Variables: Variables declared within a class represent the state or data of the class. They can have different access modifiers.
Methods (Functions): Methods define the behavior of the class. They can be void (not returning any value) or returning a specific data type.

Constructors

Constructors are special methods invoked when an object of a class is created. They initialize the object's state. In Apex, constructors have the same name as the class and no return type. They are typically used to initialize member variables.

Instantiation

Once a class is defined, you can create instances (objects) of that class using the new keyword. For example:

MyClass obj = new MyClass();

Example

Here's a simple example illustrating a class in Apex:

public class Car {
    // Class variables
    public String make;
    public Integer year;

    // Constructor
    public Car(String make, Integer year) {
        this.make = make;
        this.year = year;
    }

    // Method to display car information
    public void displayInfo() {
        System.debug('Make: ' + make);
        System.debug('Year: ' + year);
    }
}

Using Classes

Once a class is defined, you can use its methods and access its variables within your Apex code. For example:

Car myCar = new Car('Toyota', 2020);
myCar.displayInfo();

Classes are fundamental building blocks of custom business logic in the Salesforce platform. They enable developers to create modular, reusable code that enhances the functionality of Salesforce applications.

https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_ref_guide.htm

Key concepts related to classes in Salesforce Apex