What is Apex ?

Apex provides a performance advantage over interpreted languages like JavaScript. It also supports features like static typing, exception handling, and interfaces, which makes it a robust and reliable language for enterprise-level applications. 

Features of Apex:

The Apex programming language used by the Salesforce platform is evolving to meet the changing needs of administrators and developers.

1) Object-oriented programming: Apex is an object-oriented programming language that uses classes, objects, and inheritance to create reusable code. 

  2) Triggers and controllers: Triggers are used to execute code before or after a record is inserted, updated, or deleted in Salesforce. Controllers are used to manage the flow of data between a user interface and the Salesforce database.

  3) Database integration: SOQL (Salesforce Object Query Language) and SOSL (Salesforce Object Search Language) are two query languages that Apex uses to interact with the Salesforce database. 

  4) Exception handling: Apex has robust exception-handling capabilities, which makes it easier to write code that can handle errors and unexpected events. 

  5) Security: Apex is executed within the Salesforce platform and is subject to Salesforce's security protocols making applications secure and protected from unauthorized access. 

  6) Batch Apex:  A feature that allows developers to process large amounts of data in chunks,  helps to avoid hitting Salesforce's governor limits. 

  7) Testing and debugging: Apex has a comprehensive testing framework that allows developers to write unit tests and integration tests .The Apex Debug Log is a powerful tool that helps developers to identify and fix errors in their code. 

  8) Integration with other systems: Apex can be used to integrate Salesforce with other systems, such as REST and SOAP APIs. This allows developers to build custom integrations that are specific to their business needs.

What are Annotations: 

 Annotations are a powerful feature introduced in Apex that allows developers to add metadata to Apex classes, triggers, methods, and variables. These metadata annotations provide additional information to the compiler and runtime environment, enabling better code analysis and execution. 

 Types of annotations in apex: 

  1. @AuraEnabled: Used to expose Apex methods to the Lightning Component framework. It allows the method to be called from Lightning components. 

  2. @TestVisible: Used to make private or protected methods and variables visible to test methods. It is primarily used for unit testing. 

  3. @Deprecated: Used to mark a method or class as deprecated, indicating that it is no longer recommended for use. It helps developers identify outdated or unsupported code. 

  4. @RemoteAction: Used to expose static methods as remote actions that can be invoked from Visualforce pages or Lightning components.

  5. @Future: Used to indicate that a method should be executed asynchronously in the future. It is commonly used for long-running or resource-intensive operations. 

  6. @ReadOnly: Used to indicate that a method or class does not modify the state of the database. It is used to enforce read-only access for certain operations. 

  7. @IsTest: Used to indicate that a method is a test method. It is required for methods that are part of Apex test classes. 

  8. @RestResource: Used to expose an Apex class as a RESTful web service. It allows the class to handle HTTP requests and provide responses in JSON or XML format.

Use Case of Annotation: 

Here's a simple use case demonstrating the use of the @future annotation in Salesforce Apex:

Let's say you have a requirement to send an email notification to a user after a certain event, but you don't want to hold up the main transaction to send the email. You can use the @future annotation for this purpose.

In this example, we have a method sendEmailNotification annotated with @future. This method will be executed asynchronously, allowing the main transaction to proceed without waiting for the email to be sent.

To use this method in a trigger, for instance, you could call it like this:

In this trigger, after an Event record is inserted, it triggers the sendEmailNotification method asynchronously to send an email notification to a specified recipient with the subject and body content.

 The @future annotation ensures that the email-sending process happens in the background, separate from the main transaction.