The final Keyword

Sometimes, we require a variable to not actually be a variable in Java programs. This means that the value of the variable should not change during the execution of the program. For example, if you’re using a double type variable, pi, to store the value of $\pi$, which is a mathematical constant, you wouldn’t want to accidentally update it. Thus, for situations like these, we have the keyword: final.

The final keyword

To declare an unchangeable variable, just add final before the type and name of the variable as shown here:

final type name;

You can either initialize the variable straight away by using the ...