JAVA Interfaces and Abstract Classes In Java, declaring a class abstract is useful To prevent developers from further extending the class. To force developers to extend the class not to use its capabilities. When default implementations of some methods are not desirable. When it doesn't make sense to have objects of that class. When it makes sense to have objects of that class. To prevent developers from further extending the class. To force developers to extend the class not to use its capabilities. When default implementations of some methods are not desirable. When it doesn't make sense to have objects of that class. When it makes sense to have objects of that class. ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Runnable is a _____ . class abstract class vaiable interface method class abstract class vaiable interface method ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Determine output of the following code.interface A { }class C { }class D extends C { }class B extends D implements A { }public class Test extends Thread{ public static void main(String[] args){ B b = new B(); if (b instanceof A) System.out.println("b is an instance of A"); if (b instanceof C) System.out.println("b is an instance of C"); }} b is an instance of Nothing. b is an instance of A followed by b is an instance of b is an instance of b is an instance of Nothing. b is an instance of A followed by b is an instance of b is an instance of ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes interface Base{ boolean m1 (); byte m2(short s);}which two code fragments will compile?1. interface Base2 implements Base {}2. abstract class Class2 extends Base { public boolean m1(){ return true; }}3. abstract class Class2 implements Base {}4. abstract class Class2 implements Base { public boolean m1(){ return (7 > 4); }}5. abstract class Class2 implements Base { protected boolean m1(){ return (5 > 7) }} 4 and 5 1 and 2 1 and 3 3 and 4 2 and 3 4 and 5 1 and 2 1 and 3 3 and 4 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following statements regarding abstract classes are true? A subclass can override a concrete method in a superclass to declare it abstract. An abstract class can be used as a data type. An abstract class can be extended. A subclass of a non-abstract superclass can be abstract. All of these A subclass can override a concrete method in a superclass to declare it abstract. An abstract class can be used as a data type. An abstract class can be extended. A subclass of a non-abstract superclass can be abstract. All of these ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes What will be the output when the following program is compiled and executed?abstract class TestAbstract{ String my_name; String myName(){ my_name = "Examveda"; return my_name; } abstract void display();}public class Test extends TestAbstract{ void display(){ String n = myName(); System.out.print("My name is "+ n); } public static void main(String args[]){ Test t = new Test(); t.display(); }} Program will compile and execute successfully and prints Compilation error as class can not be declared as abstract. None of these Compilation error occurs as the abstract class TestAbstract contains a non-abstract method. Program compiles but leads to runtime exception. Program will compile and execute successfully and prints Compilation error as class can not be declared as abstract. None of these Compilation error occurs as the abstract class TestAbstract contains a non-abstract method. Program compiles but leads to runtime exception. ANSWER DOWNLOAD EXAMIANS APP
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