REVATURE TECHNICAL INTERVIEW INTERVIEW
QUESTIONS APPLICABLE TO SOFTWARE ENGINEERING
INTERVIEW QUESTIONS AND CORRECT DETAILED
ANSWERS WITH RATIONALES|GUARANTEED PASS
Object - ANSWER: An instance of a class
Class - ANSWER: Blueprint/prototype from which objects are created
Inheritance - ANSWER: subclasses can inherit states/behaviors of superclasses
interface - ANSWER: contract between class and outside world; when a class
implements an interface, it promises to provide the behavior published by that
interface
package - ANSWER: a namespace for organizing classes & interfaces in a logical
manner; makes large software projects easier to manage
Encapsulation - ANSWER: Hiding the internal state of an object and requiring all
interaction to be performed through an object's methods (accessors and mutators).
Example: In a Bicycle class, method changeGear() could be implemented so as to
only accept values between 1 and 6
Benefits of Objects - ANSWER: Modularity
Information-Hiding
Code re-use
Pluggability and debugging ease
Modularity - ANSWER: source code for an object can be written/maintained
independently of source code for other objects. objects can be easily passed around
the system once they've been created.
Information-Hiding - ANSWER: By interacting only with object's methods, details of
internal implementation stay secret from outside world.
Code re-use - ANSWER: Complex objects only need to be coded once; you can use
classes that have already been created by others.
Pluggability/Debugging Ease - ANSWER: If an object is causing problems, you can
easily remove it and put something else in its place.
Example: replace a bolt that is broken, not the whole machine.
,How to use the changeGear() method on a Bicycle bike1? - ANSWER:
bike1.changeGear();
How many superclasses can a subclass have? - ANSWER: ONLY ONE
How many subclasses can inherit from the same superclass? - ANSWER: Infinitely
many
What is the main benefit of using inheritance? - ANSWER: The subclass contains all
of the methods/fields of the superclass, but the subclass' code focuses on the unique
aspects, making code simpler and easier to read.
Why must the superclass' code be carefully documented? - ANSWER: Because that
code is not physically in the subclass.
Interface - ANSWER: the methods that a class is required to contain; empty methods
that are related
Should the methods in an interface be public or private? - ANSWER: MUST be public
Packages - ANSWER: organizes a set of related classes/interfaces; like a folder on
your computer
class library - ANSWER: a set of packages
API - ANSWER: Application Programming Language: Java's library of classes that you
can use in your own applications.
What do the Java API's packages represent? Give examples. - ANSWER: tasks for
general purpose programming: String, File, Socket, some for developing GUIs.
What is a benefit of using packages? - ANSWER: It allows developers to focus on the
design of an application and NOT the technical stuff that makes it work.
Real-world objects contain BLANK and BLANK. - ANSWER: State, behavior
A software object's state is stored in BLANK - ANSWER: fields
A software object's behavior is exposed through BLANK - ANSWER: methods
(functions)
Hiding internal data from the outside world, and accessing it only through publicly
exposed methods is known as data BLANK - ANSWER: Encapsulation
A blueprint for a software object is called a BLANK - ANSWER: class
,Common behavior can be defined in a BLANK and inherited into a BLANK using the
BLANK keyword - ANSWER: superclass, subclass, extends
A collection of methods with no implementation is called an BLANK - ANSWER:
interface
A namespace that organizes classes and interfaces by functionality is called a BLANK
- ANSWER: package
The term API stands for BLANK - ANSWER: Application Programming Interface
Major Principles of Object-Oriented Programming - ANSWER: Encapsulation
Abstraction
Inheritance
Polymorphism
Accessor - ANSWER: method used to ask an object about itself
Should an accessor be public or private? - ANSWER: must be public
An accessor is any public method that gives information about the BLANK of an
object. - ANSWER: state
Mutator - ANSWER: public methods used to modify the state of an object while
hiding the implementation of the method
Benefits of Encapsulation - ANSWER: 1. You can make changes to a class without
breaking other code using that class.
2. You can handle situations where the class is being used improperly in such a way
that the code doesn't fail.
Abstraction - ANSWER: development of classes/objects/types in terms of interfaces
and functionality, instead of implementation details;
development of a software object to represent a real-world object.
Main benefit of abstraction - ANSWER: manages complexity
How does abstraction manage complexity? - ANSWER: Decomposes complex
systems into smaller components;
You know what behavior to expect from the object even before it is fully
implemented, so it won't have a negative impact on later coding if it isn't completely
finished.
, Benefit of inheritance - ANSWER: Don't have to re-use the code for characteristics
shared by all of a type/group of objects
Superclass - ANSWER: only contain info common to all of its subclasses
Types of Polymorphism - ANSWER: 1. Overriding
2. Overloading
Overriding - ANSWER: Run-time polymorphism is determined at run-time based on
the type of the object
Overloading - ANSWER: Compile-time polymorphism: the compiler determines which
method will be executed based on which parameters were supplied. Multiple
methods with different signatures (different parameters).
Can you override a method in a subclass that has a different signature in its
superclass? - ANSWER: NO, in order to override the method must have the same
signature in both the subclass and the base (super) class.
Primary goal of software architecture - ANSWER: define the non-functional
requirements of a system and define the environment; consists of the design
followed by a definition of how to deliver the functional behavior within the
architectural rules
Benefits of software architecture - ANSWER: Controls Complexity
Enforces best practices
Consistency/uniformity
Increases predictability
Enables re-use
Behavior - ANSWER: set of activities performed by an object
What does a class consist of? - ANSWER: Name, attributes and operations (state and
behavior)
5 Principles of designing a Class - ANSWER: 1. SRP (Single Responsibility Principle)
2. OCP (Open Closed Principle)
3. LSP (Liskov Substitution Principle)
4. DIP (Dependency Inversion Principle)
5. ISP (Interface Segregation Principle)
QUESTIONS APPLICABLE TO SOFTWARE ENGINEERING
INTERVIEW QUESTIONS AND CORRECT DETAILED
ANSWERS WITH RATIONALES|GUARANTEED PASS
Object - ANSWER: An instance of a class
Class - ANSWER: Blueprint/prototype from which objects are created
Inheritance - ANSWER: subclasses can inherit states/behaviors of superclasses
interface - ANSWER: contract between class and outside world; when a class
implements an interface, it promises to provide the behavior published by that
interface
package - ANSWER: a namespace for organizing classes & interfaces in a logical
manner; makes large software projects easier to manage
Encapsulation - ANSWER: Hiding the internal state of an object and requiring all
interaction to be performed through an object's methods (accessors and mutators).
Example: In a Bicycle class, method changeGear() could be implemented so as to
only accept values between 1 and 6
Benefits of Objects - ANSWER: Modularity
Information-Hiding
Code re-use
Pluggability and debugging ease
Modularity - ANSWER: source code for an object can be written/maintained
independently of source code for other objects. objects can be easily passed around
the system once they've been created.
Information-Hiding - ANSWER: By interacting only with object's methods, details of
internal implementation stay secret from outside world.
Code re-use - ANSWER: Complex objects only need to be coded once; you can use
classes that have already been created by others.
Pluggability/Debugging Ease - ANSWER: If an object is causing problems, you can
easily remove it and put something else in its place.
Example: replace a bolt that is broken, not the whole machine.
,How to use the changeGear() method on a Bicycle bike1? - ANSWER:
bike1.changeGear();
How many superclasses can a subclass have? - ANSWER: ONLY ONE
How many subclasses can inherit from the same superclass? - ANSWER: Infinitely
many
What is the main benefit of using inheritance? - ANSWER: The subclass contains all
of the methods/fields of the superclass, but the subclass' code focuses on the unique
aspects, making code simpler and easier to read.
Why must the superclass' code be carefully documented? - ANSWER: Because that
code is not physically in the subclass.
Interface - ANSWER: the methods that a class is required to contain; empty methods
that are related
Should the methods in an interface be public or private? - ANSWER: MUST be public
Packages - ANSWER: organizes a set of related classes/interfaces; like a folder on
your computer
class library - ANSWER: a set of packages
API - ANSWER: Application Programming Language: Java's library of classes that you
can use in your own applications.
What do the Java API's packages represent? Give examples. - ANSWER: tasks for
general purpose programming: String, File, Socket, some for developing GUIs.
What is a benefit of using packages? - ANSWER: It allows developers to focus on the
design of an application and NOT the technical stuff that makes it work.
Real-world objects contain BLANK and BLANK. - ANSWER: State, behavior
A software object's state is stored in BLANK - ANSWER: fields
A software object's behavior is exposed through BLANK - ANSWER: methods
(functions)
Hiding internal data from the outside world, and accessing it only through publicly
exposed methods is known as data BLANK - ANSWER: Encapsulation
A blueprint for a software object is called a BLANK - ANSWER: class
,Common behavior can be defined in a BLANK and inherited into a BLANK using the
BLANK keyword - ANSWER: superclass, subclass, extends
A collection of methods with no implementation is called an BLANK - ANSWER:
interface
A namespace that organizes classes and interfaces by functionality is called a BLANK
- ANSWER: package
The term API stands for BLANK - ANSWER: Application Programming Interface
Major Principles of Object-Oriented Programming - ANSWER: Encapsulation
Abstraction
Inheritance
Polymorphism
Accessor - ANSWER: method used to ask an object about itself
Should an accessor be public or private? - ANSWER: must be public
An accessor is any public method that gives information about the BLANK of an
object. - ANSWER: state
Mutator - ANSWER: public methods used to modify the state of an object while
hiding the implementation of the method
Benefits of Encapsulation - ANSWER: 1. You can make changes to a class without
breaking other code using that class.
2. You can handle situations where the class is being used improperly in such a way
that the code doesn't fail.
Abstraction - ANSWER: development of classes/objects/types in terms of interfaces
and functionality, instead of implementation details;
development of a software object to represent a real-world object.
Main benefit of abstraction - ANSWER: manages complexity
How does abstraction manage complexity? - ANSWER: Decomposes complex
systems into smaller components;
You know what behavior to expect from the object even before it is fully
implemented, so it won't have a negative impact on later coding if it isn't completely
finished.
, Benefit of inheritance - ANSWER: Don't have to re-use the code for characteristics
shared by all of a type/group of objects
Superclass - ANSWER: only contain info common to all of its subclasses
Types of Polymorphism - ANSWER: 1. Overriding
2. Overloading
Overriding - ANSWER: Run-time polymorphism is determined at run-time based on
the type of the object
Overloading - ANSWER: Compile-time polymorphism: the compiler determines which
method will be executed based on which parameters were supplied. Multiple
methods with different signatures (different parameters).
Can you override a method in a subclass that has a different signature in its
superclass? - ANSWER: NO, in order to override the method must have the same
signature in both the subclass and the base (super) class.
Primary goal of software architecture - ANSWER: define the non-functional
requirements of a system and define the environment; consists of the design
followed by a definition of how to deliver the functional behavior within the
architectural rules
Benefits of software architecture - ANSWER: Controls Complexity
Enforces best practices
Consistency/uniformity
Increases predictability
Enables re-use
Behavior - ANSWER: set of activities performed by an object
What does a class consist of? - ANSWER: Name, attributes and operations (state and
behavior)
5 Principles of designing a Class - ANSWER: 1. SRP (Single Responsibility Principle)
2. OCP (Open Closed Principle)
3. LSP (Liskov Substitution Principle)
4. DIP (Dependency Inversion Principle)
5. ISP (Interface Segregation Principle)
