Using the final Keyword

Using the final Keyword

You can use the final keyword to modify variables.Final variables can only be assigned a value once, either when you declare a variable or inside a constructor. You must assign a value to it in one of these two places.
Static final variables can be changed in static initialization code or where defined.Member final variables can be changed in initialization code blocks, constructors, or with other variable declarations.
To define a constant, mark a variable as both static and final.Non-final static variables are used to communicate state at the class level (such as state between triggers). However, they are not shared across requests.
Methods and classes are final by default. You cannot use the final keyword in the declaration of a class or method. This means they cannot be overridden. Use the virtual keyword if you need to override a method or class.