Question 1. What is the result of compiling and running the following code?class Base{ public Base(){ System.out.print("Base"); }}public class Derived extends Base{ public Derived(){ this("Examveda"); System.out.print("Derived"); } public Derived(String s){ System.out.print(s); } public static void main(String[] args){ new Derived(); }}
Question 2. What is the output of the following program code?abstract class C1{public C1(){ System.out.print(1); } } class C2 extends C1{ public C2(){ System.out.print(2); } } class C3 extends C2{ public C3(){ System.out.println(3); } } public class Test{ public static void main(String[] a){ new C3(); } }
Question 3. Which of the following is true?1. A class can extend more than one class.2. A class can extend only one class but many interfaces.3. An interface can extend many interfaces.4. An interface can implement many interfaces.5. A class can extend one class and implement many interfaces.
Answer: Option A. -> "X extends Y" is correct if X and Y are either both classes or both interfaces
Question 5. The concept of multiple inheritance is implemented in Java byI. Extending two or more classes.II. Extending one class and implementing one or more interfaces.III. Implementing two or more interfaces.
Question 6. What is the result of compiling and running this program?class Mammal{ void eat(Mammal m){ System.out.println("Mammal eats food"); }}class Cattle extends Mammal{ void eat(Cattle c){ System.out.println("Cattle eats hay"); }}class Horse extends Cattle{ void eat(Horse h){ System.out.println("Horse eats hay"); }}public class Test{ public static void main(String[] args){ Mammal h = new Horse(); Cattle c = new Horse(); c.eat(h); }}
Question 7. Determine output:class A{public void method1(){System.out.print("Class A method1");}}class B extends A{public void method2(){System.out.print("Class B method2");}}class C extends B{public void method2(){System.out.print("Class C method2");}public void method3(){System.out.print("Class C method3");}}public class Test{public static void main(String args[]){A a = new A();C c = new C();c.method2();a = c;a.method3();}}
Question 8. What will be the result after compiling this code?class SuperClass{ public int doIt(String str, Integer... data)throws Exception{ String signature = "(String, Integer[])"; System.out.println(str + " " + signature); return 1; }}public class Test extends SuperClass{ public int doIt(String str, Integer... data){ String signature = "(String, Integer[])"; System.out.println("Overridden: " + str + " " +signature); return 0; } public static void main(String... args){ SuperClass sb = new Test(); sb.doIt("hello", 3); }}
Question 9. What will be the output?class One{ final int a = 15;}class Two extends One{ final int a = 20;}public class Test extends Two{ final int a = 30; public static void main(String args[]){ Test t = new One(); System.out.print(t.a); }}
Question 10. What will be the output?class Parent{ public void method(){ System.out.println("Hi i am parent"); }}public class Child extends Parent{ protected void method(){ System.out.println("Hi i am Child"); } public static void main(String args[]){ Child child = new Child(); child.method(); }}