JAVA Interfaces and Abstract Classes In Java, declaring a class abstract is useful When it makes sense to have objects of that class. To force developers to extend the class not to use its capabilities. When default implementations of some methods are not desirable. To prevent developers from further extending the class. When it doesn't make sense to have objects of that class. When it makes sense to have objects of that class. To force developers to extend the class not to use its capabilities. When default implementations of some methods are not desirable. To prevent developers from further extending the class. When it doesn't make sense to have objects of that class. ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following declares an abstract method in an abstract Java class? public void method() {} public abstract void method(); public abstract void method() {} public void abstract Method(); public abstract method(); public void method() {} public abstract void method(); public abstract void method() {} public void abstract Method(); public abstract method(); ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following statements regarding abstract classes are true? 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 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. 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 b is an instance of b is an instance of A followed by b is an instance of Nothing. b is an instance of b is an instance of b is an instance of A followed by b is an instance of Nothing. 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(); }} Compilation error as class can not be declared as abstract. Program will compile and execute successfully and prints Program compiles but leads to runtime exception. None of these Compilation error occurs as the abstract class TestAbstract contains a non-abstract method. Compilation error as class can not be declared as abstract. Program will compile and execute successfully and prints Program compiles but leads to runtime exception. None of these Compilation error occurs as the abstract class TestAbstract contains a non-abstract method. ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes What will be the output?interface A{public void method();}class One{public void method(){System.out.println("Class One method");}}class Two extends One implements A{public void method(){System.out.println("Class Two method");}}public class Test extends Two{public static void main(String[] args){A a = new Two();a.method();}} will print Class Two method Compilation Error will print Class One method compiles fine but print nothing None of these will print Class Two method Compilation Error will print Class One method compiles fine but print nothing None of these ANSWER DOWNLOAD EXAMIANS APP
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