JAVA Interfaces and Abstract Classes In Java, declaring a class abstract is useful When default implementations of some methods are not desirable. When it makes sense to have objects of that class. To force developers to extend the class not to use its capabilities. To prevent developers from further extending the class. When it doesn't make sense to have objects of that class. When default implementations of some methods are not desirable. When it makes sense to have objects of that class. To force developers to extend the class not to use its capabilities. 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 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();}} compiles fine but print nothing Compilation Error will print Class Two method will print Class One method None of these compiles fine but print nothing Compilation Error will print Class Two method will print Class One method None of these 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 b is an instance of A followed by b is an instance of b is an instance of Nothing. b is an instance of b is an instance of A followed by b is an instance of ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following is a correct interface? interface A { void print(); } abstract interface A { print(); } abstract interface A { abstract void print(); { }} interface A { void print() { } } interface A { void print(); } abstract interface A { print(); } abstract interface A { abstract void print(); { }} interface A { void print() { } } ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following class definitions defines a legal abstract class? abstract class A { abstract void unfinished(); } class A { abstract void unfinished() { } } public class abstract A { abstract void unfinished(); } class A { abstract void unfinished(); } abstract class A { abstract void unfinished(); } class A { abstract void unfinished() { } } public class abstract A { abstract void unfinished(); } class A { abstract void unfinished(); } 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(); }} None of these Compilation error as class can not be declared as abstract. Program compiles but leads to runtime exception. Compilation error occurs as the abstract class TestAbstract contains a non-abstract method. Program will compile and execute successfully and prints None of these Compilation error as class can not be declared as abstract. Program compiles but leads to runtime exception. Compilation error occurs as the abstract class TestAbstract contains a non-abstract method. Program will compile and execute successfully and prints ANSWER DOWNLOAD EXAMIANS APP
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