Classes and Objects

Question 1

A class ___ and ___ are optional.

Answer 1

header; body

Question 2

Classes can have a ___ ___ and one or more ___ ___’s.

Answer 2

primary constructor; secondary constructor

Question 3

‘constructor’ can be omitted if the primary constructor doesn’t have any ___ or ___ ___.

Answer 3

annotations; visibility modifiers

Question 4

In a class initialization code is placed inside ___ ___.

Answer 4

initializer blocks

Question 5

A class can contain multiple ___ blocks.

Answer 5

initialization

Question 6

You can use a ___ ___ when declaring class properties.

Answer 6

trailing comma

Question 7

Secondary constructors are prefixed with the ___ keyword.

Answer 7

constructor

Question 8

Each secondary constructor needs to ___ to the primary constructor (directly or indirectly).

Answer 8

delegate

Question 9

Code in initializer blocks becomes part of the ___ ___.

Answer 9

primary constructor

Question 10

Code in all ___ ___ and ___ ___ is executed before the secondary constructor body.

Answer 10

initializer blocks; property initializers

Question 11

What are the 5 things classes can contain?

Answer 11

constructors and initializer blocks; functions; properties; nested and inner classes; object declarations

Question 12

All classes have a common superclass ___.

Answer 12

Any

Question 13

Mark a class with ___ to make it inheritable.

Answer 13

open

Question 14

If the derived class has a primary constructor, the ___ ___ must be initialized there.

Answer 14

base class

Question 15

If the derived class has no primary constructor, each ___ ___ has to initialize it using the ___ keyword.

Answer 15

secondary constructor; super

Question 16

The explicit modifiers for overridable members are ___ and ___.

Answer 16

open; override

Question 17

Members marked ___ is itself ‘open’.

Answer 17

override

Question 18

To prohibit re-overriding, use ___.

Answer 18

final

Question 19

Properties declared in a superclass that are then redeclared in a derived class must be prefaced with ___.

Answer 19

override

Question 20

You can override a ‘val’ property with a ___ property, but not vice versa.

Answer 20

var

Question 21

You can use override keyword as part of the ___ ___ in a primary constructor.

Answer 21

property declaration

Question 22

Code in derived classes can call superclass functions using the ___ keyword.

Answer 22

super

Question 23

Inside an inner class, accessing the superclass of the outer class is done with the ___ keyword qualified with the ___ ___ ___.

Answer 23

super; outer class name

Question 24

To denote the supertype from which an inherited implementation is taken, we use ___ qualified by the ___ ___ in angle brackets.

Answer 24

super; supertype name

Question 25

True or false: We can override a non-abstract open member with an abstract one.

Answer 25

true

Question 26

If you need to write a function that can be called without having a class instance but needs access to the internals of a class, you can write it as a member of an ___ declaration.

Answer 26

object

Question 27

If you declare a ___ ___ inside your class, you can access its members using only the class name as a qualifier.

Answer 27

companion object