Revature Technical Interview(30 questions with verified responses)

Revature
Technical
Answer(30
questions with
verified
responses)
What are the four pillars of object-oriented
programming? Explain? - answer -
Inheritance
- Polymorphism
- Encapsulation
- abstraction


What is a foreign key, what is a primary key?
- answer A foreign key is a key used to link

, two tables together. This is sometimes also
called as a referencing key.
A primary key is a field in a table which
uniquely identifies each row/record in a
database table. Primary keys must contain
unique values. A primary key column cannot
have NULL values.


How do you select all tables from a
database? (exact syntax) - answer SELECT *
FROM table_name;


What is abstraction / abstract class? - answer
Abstraction is a process of hiding the
implementation details and showing only
functionality to the user.
A class which is declared as abstract is
known as an abstract class. It can have
abstract and non-abstract methods. It needs
to be extended and its method implemented.
It cannot be instantiated.


Explain method overloading and method
overriding. What are the differences? -
answer If a class has multiple methods