Apex is a strongly typed, object-oriented programming language that allows developers to execute flow and transaction control statements on the Force.com platform. Apex is executed in native mode on the Force.com platform.
Apex provides developers with a set of tools to build rich and interactive applications that can be integrated with other Force.com applications. Apex code can be invoked from triggers, Visualforce pages, and web services.
Apex code can be used to:
- Automate the creation and updating of records.
- Send email
- Submit records for approval
- Callout to external web services
- Schedule the execution of code
Apex code can be executed in the following ways:
- Triggers: Automatically invoked by a database operation, such as insert, update, or delete.
- Visualforce pages: Embedded in a Visualforce page to add controller logic.
- Web services: Exposed as a web service to be invoked by an external application.
- Scheduled: Defined to run at specific times, or on a recurring schedule.
Apex code is executed in the same environment as the user who invoked the code. This allows the code to access the user's data, as well as any other data that the user has access to.
Apex code is compiled into bytecode that is executed on the Force.com platform. Apex code can be debugged in the developer console, which provides a set of tools to step through code, set breakpoints, and view variables.
Apex code can be unit tested to ensure that the code behaves as expected. Unit tests are written in Apex, and can be run in the developer console. Apex code can also be deployed to a production environment, where it can be invoked by users.