Apex is a powerful, strongly-typed, object-oriented programming language in Salesforce that allows developers to execute backend logic and automate business processes. Below is a categorized list of key Apex functionalities:
1. Object-Oriented Programming (OOP)
Classes & Objects – Define classes and create objects for structured programming.
Interfaces & Inheritance – Implement polymorphism and code reusability.
Enums– Define a fixed set of constants.
------------------------------------------------------------------------------------------------------------------------------------2. Database Operations (DML - Data Manipulation Language)
SOQL (Salesforce Object Query Language) – Query records from Salesforce objects.
SOSL (Salesforce Object Search Language) – Perform text searches across multiple objects.
DML Statements – `INSERT`, `UPDATE`, `DELETE`, `UPSERT`, `MERGE` operations on Salesforce records.
Database Methods – `Database.insert()`, `Database.update()`, `Database.delete()`, with optional `allOrNone` behavior.
------------------------------------------------------------------------------------------------------------------------------------3. Trigger Execution
Before & After Triggers – Execute actions before or after record changes.
Context Variables – Use `Trigger.new`, `Trigger.old`, `Trigger.newMap`, etc.
Bulkification – Optimize triggers to handle large data volumes efficiently.
------------------------------------------------------------------------------------------------------------------------------------4. Asynchronous Processing
Batch Apex – Process large volumes of data in chunks asynchronously.
Queueable Apex– Chainable, asynchronous processing for complex operations.
Future Methods – Run Apex asynchronously with `@future` annotation.
Scheduled Apex – Automate code execution at scheduled intervals.
------------------------------------------------------------------------------------------------------------------------------------5. Exception Handling & Debugging
Try-Catch Blocks – Handle exceptions gracefully.
Custom Exceptions – Define and throw custom exceptions for better error handling.
System.Debug() – Log execution details for debugging.
------------------------------------------------------------------------------------------------------------------------------------6. Callouts & Integrations
REST & SOAP Callouts – Integrate with external systems using HTTP callouts.
Apex Web Services – Expose Apex methods as REST or SOAP services.
Named Credentials – Secure authentication for external services.
------------------------------------------------------------------------------------------------------------------------------------7. Security & Sharing
With/Without Sharing – Control record-level access in Apex classes.
CRUD & FLS Checks – Ensure user permissions before performing DML.
User Mode vs. System Mode – Run Apex with different access levels.
------------------------------------------------------------------------------------------------------------------------------------8. Platform Events & Messaging
Event-Driven Architecture – Publish and subscribe to Platform Events.
Change Data Capture (CDC) – Track changes to records in real time.
------------------------------------------------------------------------------------------------------------------------------------9. Testing & Deployment
Apex Unit Tests – Write test methods using `@isTest` annotation.
Test Data Setup – Use `Test.startTest()` and `Test.stopTest()` for controlled testing.
Code Coverage – Ensure at least 75% code coverage for deployment.