what is string and string builder what is ref and out what is abstract class and interface
Sigiloso
abstarct class is class which is diclared with abstract keyword . abstract method dont have a method body . we can use a abstract method as well as non abstract method in abstract class interface- interface is similer to the abstract class but the diffrence is this the interface is 100% abstrac class and we cant use a no abstract method in the interface class . we can do mutiple inharitence in interface but not in abstract class...