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Consider the following pseudo Java code. Which of these options is valid in Java

ID: 3840086 • Letter: C

Question

Consider the following pseudo Java code. Which of these options is valid in Java?

class Vehicle { . . . }
class Car extends Vehicle { . . . }
class Boat extends Vehicle { . . . }
class AmphibiousVehicle extends Car, Boat { . . . }

interface Vehicle { . . . }
interface Car extends Vehicle { . . . }
interface Boat extends Vehicle { . . . }
interface AmphibiousVehicle extends Car, Boat { . . . }

class Vehicle { . . . }
abstract class Car extends Vehicle { . . . }
abstract class Boat extends Vehicle { . . . }
class AmphibiousVehicle extends Car, Boat { . . . }   

All of these above

None of these above

a.

class Vehicle { . . . }
class Car extends Vehicle { . . . }
class Boat extends Vehicle { . . . }
class AmphibiousVehicle extends Car, Boat { . . . }

b.

interface Vehicle { . . . }
interface Car extends Vehicle { . . . }
interface Boat extends Vehicle { . . . }
interface AmphibiousVehicle extends Car, Boat { . . . }

c.

class Vehicle { . . . }
abstract class Car extends Vehicle { . . . }
abstract class Boat extends Vehicle { . . . }
class AmphibiousVehicle extends Car, Boat { . . . }   

d.

All of these above

e.

None of these above

Explanation / Answer

a)   class Vehicle { }
b)   class Car extends Vehicle { }
c)   class Boat extends Vehicle { }
d)   class AmphibiousVehicle extends Car, Boat {}

a,b,c single inheritance but d is multiple inheritance.multiple inheritance not possible in java so it is not valid.

a) interface Vehicle { . . . }

     it is an interface so it is valid.


b) interface Car extends Vehicle { . . . }

    an interface can inherit another interface so it is valid.

c) interface Boat extends Vehicle { . . . }

   an interface can inherit another interface so it is valid.

d) interface AmphibiousVehicle extends Car, Boat { . . . }

    in java an interface can inherite any no of interfaceses so it is also valid.

all a,b,c,d is valid so it is valid option

a) class Vehicle { . . . }

it is just a class so it is valid

b) abstract class Car extends Vehicle { . . . }

an abstract class can extends a normal class. so it is also valid

c)abstract class Boat extends Vehicle { . . . }

an abstract class can extends a normal class. so it is also valid

d)class AmphibiousVehicle extends Car, Boat { . . . }

here a class extends two class to acheive multiple inheritance.multiple inheritance not possible in java so it is not valid.

so this option is not valid.

so only option b is valid

a)   class Vehicle { }
b)   class Car extends Vehicle { }
c)   class Boat extends Vehicle { }
d)   class AmphibiousVehicle extends Car, Boat {}

a,b,c single inheritance but d is multiple inheritance.multiple inheritance not possible in java so it is not valid.

a) interface Vehicle { . . . }

     it is an interface so it is valid.


b) interface Car extends Vehicle { . . . }

    an interface can inherit another interface so it is valid.

c) interface Boat extends Vehicle { . . . }

   an interface can inherit another interface so it is valid.

d) interface AmphibiousVehicle extends Car, Boat { . . . }

    in java an interface can inherite any no of interfaceses so it is also valid.

all a,b,c,d is valid so it is valid option

a) class Vehicle { . . . }

it is just a class so it is valid

b) abstract class Car extends Vehicle { . . . }

an abstract class can extends a normal class. so it is also valid

c)abstract class Boat extends Vehicle { . . . }

an abstract class can extends a normal class. so it is also valid

d)class AmphibiousVehicle extends Car, Boat { . . . }

here a class extends two class to acheive multiple inheritance.multiple inheritance not possible in java so it is not valid.

so this option is not valid.