Classes and Casting

In general, all type information is available at runtime. This means that Apex enables casting, that is, a data type of one class can be assigned to a data type of another class, but only if one class is a child of the other class. Use casting when you want to convert an object from one data type to another.

In the following example, CustomReport extends the class Report. Therefore, it is a child of that class. This means that you can use casting to assign objects with the parent data type (Report) to the objects of the child data type (CustomReport).

In the following code block, first, a custom report object is added to a list of report objects. After that, the custom report object is returned as a report object, then is cast back into a custom report object.

Casting Example

In addition, an interface type can be cast to a sub-interface or a class type that implements that interface.