JAVA INHERITENCE QUIZ

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(); }}

ExamiansBaseDerived

ExamiansDerived

ExamiansDerivedBase

BaseExamiansDerived

Compilation Error

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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.

1 and 2

2 and 5

3 and 4

3 and 5

2 and 4

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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); }}

Class cast Exception at runtime.

prints "Mammal eats food"

prints "Cattle eats hay"

None of these

prints "Horse eats hay"

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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();}}

Class B method2 Class C method3

Compilation Error

None of these

Runtime exception

Class C method2 Class C method3

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Determine output:class Small{ public Small(){ System.out.print("a "); }}class Small2 extends Small{ public Small2(){ System.out.print("b "); }}class Small3 extends Small2{ public Small3(){ System.out.print("c "); }}public class Test{ public static void main(String args[]){ new Small3(); }}

c

a b c

The code runs without output..

c b a

a

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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); }}

30

15

20

None of these

Compiler Error

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Which is true?

"X extends Y" is correct for all combinations of X and Y being classes and/or interfaces

"X extends Y" is correct if and only if X is an interface and Y is a class

"X extends Y" is correct if and only if X is a class and Y is an interface

"X extends Y" is correct if X and Y are either both classes or both interfaces

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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(); }}

Run Time error

Compiles successfully and print

Compile time error

None of This

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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); }}

Compilation fails

hello (String, Integer[])

None of these

Overridden: hello (String, Integer[])

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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.

Only (II)

(I) and (II)

Only (III)

(II) and (III)

Only (I)

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