Suppose you have a Java class, Student, which needs to keep track of an ID number for each student object that is created. This ID number needs to be different for each student, but once it has been assigned to a particular student, its value should not be changed.

What is the best way of defining and initialising the ID variable?

Question $10$Answer

a$.$

As a constant instance variable, i$.$e$.,$private final int ID$,$ whose value is set by the class constructor.

b$.$

As a non$-$final instance variable, i$.$e$.,$private int ID$,$ whose value is set by the class constructor.

c$.$

As a constant class variable, i$.$e$.,$ public static final int ID $=12345678$;

d$.$

As a non$-$final class variable, i$.$e$.,$private static int ID$,$ whose value is set by the class constructor.

Clear my choice