Note: This release is in preview. Features described here don’t become generally available until the latest general availability date that Salesforce announces for this release. Before then, and where features are noted as beta, pilot, or developer preview, we can’t guarantee general availability within any particular time frame or at all. Make your purchase decisions only on the basis of generally available products and features.
Apex Developer Guide
Apex is a strongly typed, object-oriented programming language that allows developers
to execute flow and transaction control statements on the Salesforce Platform server, in
conjunction with calls to the API. This guide introduces you to the Apex development process
and provides valuable information on learning, writing, deploying and testing
Apex.
For reference information on Apex classes, interfaces, exceptions and so on, see Apex Reference Guide.