Difference between Class variables and Reference variables

Question

Static int a; // Class Variables Student abc = new Student(); // Reference Variables

Vulpes · Answer

'abc' could be a private instance variable (if it's declared at class level) or a local variable (if it's defined within a method or property). If Student is a class then it's a reference type or object variable. If Student is a struct then it's a value type or value variable. The term 'object' is not normally used with value types in .NET. However the term 'instance' can be applied to either classes or structs so 'abc' could be termed an instance variable in either case.

Brijesh Gajjar · Answer

Thanks.... Student abc = new Student(); is a object variable or reference variables ?

Vulpes · Answer

Class (or static) variables apply to the class as a whole and not to a particular instance of it. Consequently there is only one copy of a class variable which persists for the lifetime of the application. In contrast instance variables apply to a particular instance and so each instance has its own copy which persists until the instance is garbage collected. From outside the class and provided they are accessible class variables are always accessed by prefixing them with the class name whereas instance variables are accessed through a reference to the instance in question.