Apex Language Fundamentals

Apex ProgrammingApex Language FundamentalsA thorough tour of Apex, the strongly typed, Java-like language that runs inside the multi-tenant Salesforce platform: types and their quirks, sObjects, collections, OOP, exceptions, modern operators, dynamic Apex and the standard namespaces.Beginner · about 80 minutesWhat you will learn

Explain how Apex is compiled, stored and executed on a multi-tenant platform and why governor limits exist

Use primitive types correctly, including Decimal precision, String comparison and Datetime time zones

Choose between List, Set and Map, and build Map<Id, SObject> indexes from query results

Write classes, interfaces, abstract/virtual hierarchies, enums, properties and custom exceptions

Use modern syntax: switch on, safe navigation (?.), null coalescing (??) and Comparator-based sorting

Instantiate types dynamically with Type.forName and work with JSON and the Schema namespace

Contents

What Apex is and how it runs

Primitive types and their quirks

sObjects

Collections: List, Set and Map

Control flow

Classes, interfaces and inheritance

Exceptions

Modern operators: ?. and ??

Sorting: Comparable and Comparator

Iterable and Iterator

Dynamic Apex: Type.forName and the Schema namespace

JSON basics

Annotations overview

A tour of the standard namespaces

Versioned behaviour

Apex vs Java: the differences that bite

Worked example: a bulk-safe contact enrichment service

Best practices

Common pitfalls

Hands-on exercises

Key takeaways