Here, We see OOP LinkedIn Skill Assessment Answer. This assessment test consists of 15-20 MCQs to demonstrate your knowledge of your selected skills. MCQs come from different topics – Constructors and Destructors, Design Patterns, Four Principles of OOP, Object-Oriented Fundamentals, and Software Development.

List of all LinkedIn Skills Assessment Answer

OOP LinkedIn Skill Assessment Answer

Q1. What is an example of dynamic binding?

any method
method overloading
method overriding✔
compiling

Q2. In which case would the use of a static attribute be appropriate?

the number of people in each house in a small neighbourhood
the lot size for each house in a small neighbourhood
the colour of each house in a small neighbourhood
the weather conditions for each house in a small neighbourhood ✔

Q3. Why would you create an abstract class, if it can have no real instances?

to avoid redundant coding in children✔
to explore a hypothetical class
to prevent unwanted method implementation
to reserve memory for an unspecified class type

Q4. Why would you create an abstract class, if it can have no real instances?

to have common behaviour in derived classes✔
to explore a hypothetical class
to prevent unwanted method implementation
to reserve memory for an unspecified class type

Q5. When does static binding happen?

only when you export
both at compile time and runtime
at compile time✔
at runtime

Q6. What is the best reason to use a design pattern?

It will result in code that is more extensible and maintainable✔
It will result in a more compact product.
It will speed up initial development.
It will allow you to add that design pattern to your resume.

Q7. What is encapsulation?

defining classes by focusing on what is important for a purpose
hiding the data and implementation details within a class✔
making all methods private
using words to define classes

Q8. What is an IS-A relationship?

It implies encapsulation.
A superclass object has an IS-A relationship with its subclass.
It implies a virtual method.
A subclass object has an IS-A relationship with its superclass or interface✔

Q9. You want a method with behaviour similar to a virtual method–it is meant to be overridden –expect that it does not have a method body. It just has a method signature. What kind of method should you use?

an abstract method✔
a public internal method
an internal method
a protected internal method

Q10. Which code creates a new object from the Employee class?

Employee currentEmployee = Employee.Create();
Employee currentEmployee = new Employee();✔
Employee currentEmployee;
Employee currentEmployee = Employee.New();

Q11. Which type of constructor cannot have a return type?

default
copy
parameterized
Constructors do not have a return type✔

Q12. When is a constructor executed?

when an object is created from a class using the new keyword✔
when a class is defined using the class keyword
every time an object is referenced
when an object is created from a class using the create keyword

Q13. When is a constructor executed?

when an object is created from a class✔
when a class is defined using the class keyword
every time an object is referenced
when an object is created from a class using the create keyword

Q14. If a local class is defined in a function, what is true for an object of that class?

The object can be accessed, declared, and used locally in that function.✔
The object must be declared inside any other function.
The object is temporarily accessible outside the function.
The object can call all the other class members anywhere in the program.

Q15. Which two blocks are used to handle and check errors?

do and check
to catch and trying
try and catch✔
do and while

Q16. Why would you implement composition using an id instead of a reference?

It makes it easier to save the entity.
all of these answers✔
It can make the entity retrieval more efficient
It minimizes coupling.

Q17. Which statement best describes the method of inheritance in OOP?

Inheritance describes the ability to create new classes based on an existing class.✔
Inheritance means that a group of related properties, methods, and other members are treated as a single unit or object.
Inheritance forces a class to have a single responsibility from only one parent.
Inheritance means that you will never have multiple classes that can be used interchangeably, even though each class implements the same properties or methods in different ways.

Q18. Which type of inheritance, when done continuously, is similar to a tree structure?

multilevel
hierarchical and multiple
hierarchical✔
multiple

Q19. Which statement is true?

A default parameter’s constructor is not equivalent to the default constructor
A default constructor is inherited from a parent class
A default constructor can be called explicitly✔
A default constructor cannot be defined by the coder

reference It is even mentioned in Wikipedia: “The constructors can be called explicitly or implicitly. The method of calling the constructor implicitly is also called the shorthand method.”

Q20. Which of the following is NOT an advantage of using getters and setters?

Getters and setters can speed up compilation.✔
Getters and setters provide encapsulation of behaviour.
Getters and setters provide a debugging point for when a property changes at runtime.
Getters and setters permit different access levels.

Q21. In the context of OOP, what is association?

The association is a relationship where all objects have their life cycle and there is no owner.✔
The association is the process where model elements cooperate to provide higher-level behaviour.
The association is a whole/part relationship where one object is composed of one or more other objects, each of which is considered a part of the whole.
The association is where all objects have their life cycle, but there is ownership, and child objects can not belong to another parent object.

Reference
Association is a semantically weak relationship (a semantic dependency) between otherwise unrelated objects. An association is a “using” relationship between two or more objects in which the objects have their own lifetime and there is no owner.

Q22. How are user stories different from use cases?

User Stories are shorter and less detailed.✔
User stories are more accurate.
User stories are more detailed and structured.
User storised are more anecdotal and personal.

Q23. Which type of inheritance must be used so that the resultant is hybrid?

multiple✔
any type of inheritance
multilevel
hierarchical

reference

Q24. A language that does not support polymorphism but supports classes is considered what?

an object-based language✔
a class-based language
a procedure-oriented language
if classes are supported, polymorphism will be supported

reference

Q25. Two classes combine private data members and provide public member functions to access and manipulate those data members. Where is an abstraction used?

Abstraction is using a private access specifier for the data members.
Abstraction is using public member functions to access and manipulate the data members.✔
Abstraction is using the class concept with both data members and member functions.
There is insufficient information to decide where abstraction is being used.

Q26. What are the five Creational Design patterns of the Gang of Four?

Observer, State, Strategy, Template Method, and Visitor.
Composite, Visitor, State, Prototype, and Singleton.
Composite, Builder, Factory Method, Prototype, and Singleton.
Abstract Factory, Builder, Factory Method, Prototype, and Singleton.✔

Q27. In multilevel inheritance, one class inherits how many classes?

one class only✔
two classes
as many classes as required
at least two classes

Q28. If an object is passed by reference, the changes made in the function are reflected _.

to the main object of the caller function, too✔
on the caller function object and also the called function object
on the copy of the object that is made during the pass
only in the local scope of the called function

Q29. What is a method?

a set of instructions designed to perform a frequently used operation within a program and return no values
the same thing as a function and subroutine
a set of variables that can change over time
They are functions attached to specific classes (or instances) in object-oriented programming.✔

Q30. A mobile phone is made up of components such as a motherboard, camera, and sensors. The motherboard represents all the functions of a phone, the display shows the display only, and the phone is represented as a whole. Which of the following has the highest level of abstraction?

camera
display
motherboard
mobile phone✔

Q31. Which class has the highest degree of abstraction in a multilevel inheritance relationship of five levels?

the class at the third level
the class at the first level✔
All have the same degree of abstraction.
the class at the second level

Q32. Which is NOT one of the basic types of inheritance?

multilevel inheritance
double inheritance✔
single inheritance
hierarchical inheritance

Q33. Why is code duplication so insidious?

The duplication uses unnecessary space.
One has to maintain all the duplicates.✔
Duplication can cause intellectual property concerns.
Duplication is easy to hide.

Q34. When and how often is a static constructor called?

It is called initially when an object is created and called with every new object instance.
It is called when an object is destroyed and only one time.
It is called initially when an object is created and only one time.✔
It is created at a time when the object is discarded.

Q35. What does the code shown below demonstrate, and why?

static void Multiply(int num1, int num2) {};
   static void Multiply(double num1, double num2, double num3) {};
   static void Multiply(float num1, float num2) {};Code language: JavaScript (javascript)

polymorphism, because each method can perform different task
method overriding, because it displays the same method name, different or same parameters, and the same return type
method overloading, because it allows the creation of several methods with the same name, which differ by the type of input via parameter✔
method overriding, because it displays the same method name, different parameters, and the same return type

Q36. What is the usage of a static constructor?

to initialize all the members with a static value
to delete the static members when not required
to initialize the static members of class✔
to clear all the static members’ initialized values

Q37. What are CRC Cards?

Code Responsibility Collection cards are a brainstorming tool used in the design of procedural software
Class Responsibility collaboration cards are a brainstorming tool used in the design of OOP software✔
Code Responsibility Correction cards are tools used for debugging
Code Responsibility Correction cards are tools for modeling

reference link

Q38. How are the contents of a composition different from those of aggregation?

if one element of an aggregation is dereferenced, all its elements are eligible for garbage collection
if a composition dies, the contents die✔
the contents of a composition are all siblings
an aggregation contains only abstract classes

Q39. Which statement about compositions and aggregations is true?

if one element of an aggregation is dereferenced, all its elements are eligible for garbage collection
if a composition dies, the contents die✔
the contents of a composition are all siblings
an aggregation contains only abstract classes

Q40. What is the result of using more abstraction?

it can increase code vulnerability
it can make code unsafe
it can limit code readability✔
it can be safer for coding

Q41. Which is false for a member function of a class?

Member functions can be defined only inside or outside the class body.
Member functions can be made to be friends of another class.
Member functions do not need to be declared inside the class definition.✔
All member functions need to be defined.

Q42. Why is inheritance used when creating a new class?

to protect attributes from unwanted changes
to delegate coding responsibility more efficiently
to conserve memory
to separate class behavior from the more general to more specific✔

Q43. In addition to attributes and behaviors, what quality must a class possess?

a name✔
a state
a color
an object

Q44. Which type of function among the following shows polymorphism?

inline function
undefined function
virtual function✔
class member function

Q45. Which words in the following list are candidates for objects: trumpet, clean, enrage, leaf, tree, collapse, active, and lively?

leaf and tree
clean, enrage, and collapse
clean, active, and lively
leaf, tree, and trumpet✔

Q46. What best describes what object-oriented programming does?

It focuses on objects that interact cleanly with one another.✔
It programs exclusively to interfaces.
It programs exclusively to classes.
It creates one class for all business logic.

Q47. Can abstract classes be used in multilevel inheritance?

No, abstract classes can be used only in single-level inheritance since they must be immediately implemented.
yes, always✔
yes, but with only one abstract class
No, abstract classes do not have constructors.

Q48. What type of inheritance may lead to the diamond problem?

single level
multilevel
hierarchical
multiple✔

Q49. What is the relationship between abstraction and encapsulation?

Abstraction is about making relevant information visible, while encapsulation enables a programmer to implement the desired level of abstraction.✔
Abstraction and encapsulation are essentially the same.
Abstraction and encapsulation are unrelated.
Encapsulation is about making relevant information visible, while abstraction enables a programmer to implement the desired level of encapsulation.

Q50. Which of these keywords are access specifiers?

abstract and public
public and private✔
this and final
final and abstract

Q51. What is a reference to an object?

It is the address of a variable only — not the method of an object.
It is a shallow pointer that contains the address of an object.
It is the physical address of an object.
It is the address where the variables and methods of an object are stored.✔

Q52. Why is unit testing harder in OOP than functional programming?

Objects may maintain an internal state, which is not easily accessible by the tests.✔
The quality of unit testing frameworks for functional languages is better.
OOP promotes code reuse, which means that your tests have to consider more use cases.
Object-oriented languages tend to rely on frameworks such as Spring or Hibernate, which make them difficult to test.

Q53. What is the function of a user diagram?

It connects actors to use cases.✔
It links actors to roles played in all use cases.
It lists all actors for each use case.
It minimizes the number of actors required.

Q54. How do object behaviors and attributes differ?

Behavior describes dynamic properties; attributes are static.
Attributes describe a state; behaviors describe a change.✔
Attributes apply only to a specified object; behavior applies to other linked objects.
Behaviors are vector quantities; attributes are scalars.

Q55. The open/closed principle states that classes should be open for _ but closed for _.

refactoring; duplication
modification; duplication
extension; modification✔
reuse; encapsulation

Q56. Why would you override a method of a base class?

to define a method that must be implemented in a derived class
to define a custom implementation of an inherited member✔
to define a method that must be implemented in a superclass only
to define a class that can be inherited from

Q57. What is a copy constructor?

It is a unique constructor for creating a new object as a copy of an object that already exists. There will always be only one copy constructor that can be either defined by the user or the system.✔
It is a constructor that duplicates itself when requested on demand.
It is a common constructor for preventing the creation of a new object as a copy of an object that already exists. There will always be multiple standard constructors that can be either defined by the user or the system.
It is a constructor that duplicates itself on its own, based on the memory available.

Q58. What defines the catch block most accurately?

The catch block that will be executed is the one that best matches the type of exception thrown.✔
Multiple catch blocks can never be associated with a single try block.
Multiple catch blocks are mandatory for each try block.
Multiple catch blocks will all be executed in the case of an exception.

Q59. There are five classes. Class E is derived from class D, D from C, C from B, and B from A. Which class constructor(s) will be called first if the object of E or D is created?

A✔
B
C
C and B

Q60. You have modules that are dependent on each other. If you change one module, you have to make changes in the dependent modules. What term is used to describe this problem, and what is a potential solution?

Cohesion. A solution is to show that each module has certain responsibilities and to use an anticohesive design pattern.
Encapsulation. A solution is to implement one of the SOLID principles to ensure the modules do not encapsulate with each other.
Coupling. A solution is to refactor the code to be loosely coupled by using inversion of control and dependency injection.✔
Dependency. A solution is to implement polymorphism and abstraction to change and extract dependent elements of a module so that it functions on its own.

Q61. _ describes an aggregation

A class of resources
A group of methods
A collection of objects✔
A list of children

Q62. Which type of function can be used for polymorphism?

virtual function✔
inline function
undefined function
private function

Q63. Which choice is a benefit of using dependency injection?

loose coupling✔
code reusability
lazy initialization
data abstraction

Q64. Are you required to return an object if it was passed by reference to a function, and why or why not?

Yes, the caller function needs to reflect the changes.
No, you should use a global variable instead.
No, changes will be automatically reflected in the calling function.✔
Yes, the object must be the same in the caller function.

Q65. Why is inheritance?

Q66. What is the best example of a superclass and subclass relationship?

car:toyota✔
ducks:pond
toes:feet
rock:stone

Q67. Which statements best describe the Gang of Four design patterns called Memento and Observer?

Memento notifies multiple classes of changes. Observer captures and restores an object’s internal state.
Memento defers the exact steps of an algorithm to a subclass. Observer defines a new operation to a class without change.
Memento alters an object’s behavior when its state changes. Observer encapsulates an algorithm inside a class.
Memento captures and restores an object’s internal state. Observer notifies multiple classes of changes.✔

Q68. What does the value (0.5,0.5,0.5) indicate in the class diagram specification position: Coordinate = (0.5,0.5,0.5)?

a default value of the Coordinate attribute
the size of the position array
an increment of the position attribute value
a default value of the position attribute✔

Q69. What is the most accurate example of the Liskov substitution principle?

publicclassCar{
}
publicclassFlyingCarsextendsCar{
   publicvoidfly(){}
}
publicclassTesla FlyingCar{}
publicclassHonda Car{}

publicclassCar{
   publicvoidfly(){}
}
publicclassTeslaextendsCar{}
publicclassHondaextendsCar{}

publicclassCar{
publicvoidfly(){}
}
publicclassTesla Car{}
publicclassHonda Car{}

D✔

publicclassCar{
}
publicclassFlyingCarsextendsCar{
   publicvoidfly(){}
}
publicclassTeslaextendsFlyingCar{}
publicclassHondaextendsCar{}

reference link

Q70. What is the difference between a parameter and an argument?

An argument can have many values while a parameter can have only one value.
An argument is the variable used for input values in a method. A parameter is the specific input value passed to the method.
A parameter is a variable in the declaration of a function. An argument is the value of this variable that gets passed to the function.✔
Parameters and arguments are the same

Q71. What is the scope of a class nested inside another class?

Protected scope
Private scope
Global scope
Depends on access specifier and inheritance used✔

Q72. Methods and attributes that define an object are a kind of blueprint called what?

a collection
a variable
a class✔
a procedure

Q73. Assume single inheritance is used with classes A and B while A is the base class. Then assume classes C, D, and E, where C is a base class and D is derived from C, then E is derived from D. Class C is made to inherit from class B. Which type of inheritance is reflected?

Multilevel✔
Hybrid
Single level
Multiple

Q74. What is the main idea behind the separation of concerns?

All of these answers✔
Applications are decomposed into parts
Parts are defined with minimal overlap
Each part is responsible for a separate concern

Q75. What is the purpose of the finally block?

To always run the finally block of code when the try block exits✔
To run code when an exception has not occurred
To run the block if an exception occurred
To run code whenever garbage collection requires it

Q76. Which choice is not an OOP language?

C#
Java
C✔
Python

Q77. What is the function of a finalizer or destructor?

To relinquish resources that are no longer needed✔
To delete a variable name
To reset an attribute value
To hold space, even after an object is no longer being used

Q78. An instance of which type of class cannot be created?

Protected class
Base class
Anonymous class
Abstract class✔

Q79. In the context of OOP, what is composition?

Composition is the act of one object passing to another object an operation to be performed on behalf of the initial object.
Composition is a part/whole relationship where an object is composed of one or more other objects, each of which is considered a part of the whole.✔
Composition is binding where the class/name association is not made until the object designated by the name is created at execution time
Composition is a process of collecting classes that provide a set of services for a particular domain

Q80. Static polymorphism uses method _?

overloading✔
inheritance
abstraction
overriding

Q81. What does a concrete class not have?

parents
pure virtual functions✔
attributes
purposes

Q82. How does dynamic typing complicate troubleshooting?

It can be difficult to identify variables that are incorrectly typed✔
The dynamic variables can assume only limited values
Storage is fixed for dynamic variables
Static variables are more flexible than dynamic variables

Q83. What is the difference between early binding and late binding?

Early binding is when a variable is assigned a value when a scope is created. Late binding is when a variable is assigned a value after a scope is exited
Early binding is when a variable is assigned a value when the program starts. Late binding is when a variable is assigned after the program is running
There is no difference. In both cases, variables are assigned values when a program has completed startup and is running
Early binding is when a variable is assigned its value at compile time. Late binding is when a variable is assigned a value at run time✔

Q84. What is the difference between an interface and an abstract class?

Interfaces can contain code or data. Abstract classes do not contain code or data. A class can inherit from more than one abstract class but can implement only one interface.
Interfaces can contain code or data. Abstract classes do not contain code or data. A class can inherit from only one abstract class but can implement an unlimited number of interfaces.
Abstract classes can contain code or data. Interfaces do not contain code or data. A class can inherit from only one abstract class but can implement an unlimited number of interfaces.✔
Abstract classes can contain code or data. Interfaces do not contain code or data. A class can inherit from more than one abstract class but can implement only one interface.

Q85. What parameters are required to be passed to a class constructor?

Here they haven’t mentioned any specific language so let’s consider all languages.

reference to subclass // References to subclass is never required as you can simply Initialize subclass & use their object.
reference to base class // References to the base class are not required in Java, Javascript & Python
reference to this pointer // While Python & Javascript may require passing this or self in the constructor, It is not passed in Java constructor.
none // Above 3 are incorrect so “none” is the answer✔

Q86. What are the four principles of object-oriented programming?

manipulation, encapsulation, inheritance, and dependency inversion
dependency inversion, open/closed principle, encapsulation, and inheritance
interface segregation, abstraction, dependency inversion, and inheritance
abstraction, encapsulation, inheritance, and polymorphism✔

Q87. From the SOLID principles of object-oriented programming, which statement best describes the Liskov substitution principle?

A class should have only a single responsibility—that is, only changes to one part of the software’s specification should be able to affect the specification of the class.
Software entities should be open for extension but closed for modification.
Many client-specific interfaces are better than one general-purpose interface.
objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program.✔

Q88. In addition to responsibilities, what should be listed on Class-responsibility-collaboration (CRC) cards?

which programming language will be used.
the programmer responsible for implementation.
interacting classes.✔
attributes.

Q89. What is the best name for the function that corrects this assessment?

makeResult()
questionScore()
calculateScore()✔
getAnswers()

Q90. Which relationship best illustrates an abstract-concrete class relationship?

cat : kitten
color : red
planet : moon✔
truck : window

Q91. What cannot be used for polymorphism?

overloading constructors
overloading member functions
static member functions✔
overloading predefined operator

Q92. How many levels does multilevel inheritance allow in a program?

only 10 levels of inheritance
as many levels of inheritance as required within 10 minutes
as many levels of inheritance as required✔
only the amount of levels of memory permits, divided by processor speed

Q93. What is a virtual Method?

a method that you expect may be redefined in derived classes✔
a method that you do not expect to be redefined in derived classes
a private method that you do not expect to be redefined in derived public classes
a method that exists temporarily – once used, it ceases to be used by any caller

Q94. Which of these is not a basic principle of Object Oriented Programming?

Encapsulation
Compilation✔
Inheritance
Polymorphism

Reference

Q95. How do object behaviours and attributes differ?

Behaviour describes dynamic properties; attributes are static.
Attributes describe a state; behaviours describe a change.✔
Attributes apply only to a specified object; behaviour applies to other linked objects.
Behaviours are vector quantities; attributes are scalars.

Q96. How coupled should your classes be and why?

You should increase coupling to improve dependencies between classes.
You should limit coupling to reduce dependencies between classes.✔
You should increase coupling so that class members relate to the class purpose.
You should limit coupling so that class members relate to the class objective.

Q97. Which statement best describes a friend class?

Friend classes support base classes when necessary.
A friend class can access the private and protected members of the class in which it is declared as a friend.✔
Friend classes do not have any implementation.
A friend class can access only protected members of the class of which it is a friend.

Reference

Q98. Which code sample demonstrates multiple inheritance?

class employee{ }; class stream{ }; class topper{ };
class employee{int rating;}; class stream:public employee{ };
class employee{int rating;}; class stream{int total;}; class topper: employee, stream{ };✔
class employeef{int rating};}: class stream{ }: class topper: public employee{ }:

Q99. What is multilevel inheritance?

a class that does not have more than one parent.
a class not derived from another derived object.
not doubling single-level inheritance.
classes derived from other derived classes.✔✔

Reference

Q100. Can you have two classes with the same name in the same project?

No, you cannot.
Yes, as long as their constructors are different.
Yes, as long as their methods are different.
Yes, as long as they are in different namespaces.✔

Q101. Objects are passed by _

value or reference, depending on the programming language used
value
value or reference, depending on the program
reference✔

Q102. If a language just implements pass-by-value parameters to functions, can the objects passed as parameters be set to new instances inside the function and their new value will return to the caller?

Yes, but only if it is a reference and not a primitive class.
Yes, since the value is a reference even though it is passed by value, it can be done.
No, you will get a compilation error.
No, a local copy will be initialized and will be lost as soon as it is out of scope.✔

Q103. What is encapsulation?

defining classes by focusing on what is important for a purpose
defining data and relevant methods together in the same class✔
making all methods private
using words to define classes

Q104. What is a method?

a function associated with data and behaviour ✔
the same thing as a function and subroutine
a set of variables that can change over time
a set of instructions designed to perform a frequently used operation within a program and return no values

Q105.What is the most accurate example of the Liskov substitution principle?

A public class Car{ } public class FlyingCars extends Car{ public void fly(){} } public class Tesla FlyingCar{} public class Honda Car{}
B public class Car{ public void fly(){} } public class Tesla extends Car{} public class Honda extends Car{}
C public class Car{ public void fly(){} } public class Tesla Car{} public class Honda Car{}
D public class Car{ } public class FlyingCars extends Car{ public void fly(){} } public class Tesla extends FlyingCar{} public class Honda extends Car{}✔ reference link

Q106 What describes an aggregation

A class of resources
A group of methods
A collection of objects✔
A list of children

107. Which choice is a benefit of using dependency injection?

loose coupling✔
code reusability
lazy initialization
data abstraction

Q108. What cannot be used for polymorphism?

overloading constructors
overloading member functions
static member functions✔
overloading predefined operator

Q109. An instance of which type of class cannot be created?

Protected class
Base class
Anonymous class
Abstract class✔

Q110. From the SOLID principles of object-oriented programming, which statement best describes the Liskov substitution principle?

A class should have only a single responsibility—that is, only changes to one part of the software’s specification should be able to affect the specification of the class.
Software entities should be open for extension but closed for modification.
Many client-specific interfaces are better than one general-purpose interface.
objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program.✔

Q111. What are the five Creational Design patterns of the Gang of Four?

Observer, State, Strategy, Template Method, and Visitor.
Composite, Visitor, State, Prototype, and Singleton.
Composite, Builder, Factory Method, Prototype, and Singleton.
Abstract Factory, Builder, Factory Method, Prototype, and Singleton.✔

Q112. What is the difference between an interface and an abstract class?

Interfaces can contain code or data. Abstract classes do not contain code or data. A class can inherit from more than one abstract class but can implement only one interface.
Interfaces can contain code or data. Abstract classes do not contain code or data. A class can inherit from only one abstract class but can implement an unlimited number of interfaces.
Abstract classes can contain code or data. Interfaces do not contain code or data. A class can inherit from only one abstract class but can implement an unlimited number of interfaces.✔
Abstract classes can contain code or data. Interfaces do not contain code or data. A class can inherit from more than one abstract class but can implement only one interface.

Q113. Which relationship best illustrates an abstract-concrete class relationship?

cat : kitten
color : red
planet : moon✔
truck : window

Q114. Which choice is a benefit of using dependency injection?

loose coupling✔
code reusability
lazy initialization
data abstraction

Q115. _ describes an aggregation

A class of resources
A group of methods
A collection of objects✔
A list of children

Q116. Which type of function can be used for polymorphism?

virtual function✔
inline function
undefined function
private function

Q117. Which choice is a benefit of using dependency injection?

loose coupling✔
code reusability
lazy initialization
data abstraction

Q118. Are you required to return an object if it was passed by reference to a function, and why or why not?

Yes, the caller function needs to reflect the changes.
No, you should use a global variable instead.
No, changes will be automatically reflected in the calling function.✔
Yes, the object must be the same in the caller function.

Q119. From the SOLID principles of object-oriented programming, which statement best describes the Liskov substitution principle?

A class should have only a single responsibility—that is, only changes to one part of the software’s specification should be able to affect the specification of the class.
Software entities should be open for extension but closed for modification.
Many client-specific interfaces are better than one general-purpose interface.
objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program.✔

Q120. In addition to responsibilities, what should be listed on Class-responsibility-collaboration (CRC) cards?

which programming language will be used.
the programmer responsible for implementation.
interacting classes.✔
attributes.

Q121. What is the best name for the function that corrects this assessment?

makeResult()
questionScore()
calculateScore()✔
getAnswers()

Q122. Who invented OOP?

Andrea Ferro
Adele Goldberg
Alan Kay✔
Dennis Ritchie