WebThe instance variable is initialized at the time of the class loading or when an object of the class is created. An instance variable can be declared using different access modifiers available in Java like default, private, … WebInterfaces can't. Abstract classes can have instance variables (these are inherited Interfaces can't. Finally, a concrete class can only extend one class (abstract or However, a concrete class can implement many interfaces. This fact has nothing to do with abstract classes. have one parent class (although the parent class can have a parent
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WebDec 7, 2009 · An interface is a contract that defines the interaction between objects. This interaction is defined by the exposed methods, not by the variables. Variables would only describe the internal working, not the interaction. Note that … WebApr 16, 2015 · No interface cannot have instance variable. Interface doesnt hold by itself instance variables of its own as by default inside … high intensity pool exercises
Interfaces in Java - GeeksforGeeks
WebAug 29, 2024 · In abstract class, we have an instance variable, abstract methods, and non-abstract methods. We need to initialize the non-abstract methods and instance variables, therefore abstract classes have a constructor. Also, even if we don’t provide any constructor the compiler will add default constructor in an abstract class. Weba) You can define an interface variable that refers to an object of any class in the samepackage. b) You cannot define a variable whose type is an interface. c) You can instantiate an object from an interface class. d) You can define an interface variable that refers to an object only if the object belongsto a class that implements the interface. WebJan 24, 2024 · As you can see, an interface is declared using the Java interface keyword. Just like with classes, a Java interface can be declared public or package scope (no access modifier). The interface example above contains one variable and one method. The variable can be accessed directly from the interface, like this: high intensity portable work light