Final modifier

The final modifier applies to types (including classes), type members (variables, properties, methods), local variables, and function parameters.

The final modifier specifies that the value of a property, local variable, or parameter cannot be modified after the initial value is assigned. The final modifier cannot be combined with the abstract modifier on anything. These modifiers are mutually exclusive. The final modifier implies that there is a concrete implementation and the abstract modifier implies that there is no concrete implementation.