AverageRound

Which programming concept allows an object to take on many forms, such as an object of a subclass being treated as an object of its superclass?

• Encapsulation

• Abstraction

• Polymorphism

• Inheritance

Answer explanation

Polymorphism means 'many forms'. In OOP, it refers to the ability of an object to take on many forms, allowing a single interface to be used for general class of actions.

Which of the following best describes 'method overloading' in object-oriented programming?

• Defining multiple methods in the same class with the same name but different parameter lists.

• Defining a method in a subclass with the same signature (name and parameters) as a method in its superclass.

• Calling a method from within the same method, creating a recursive call.

• Making a method private so it can only be accessed from within its own class.

Answer explanation

Method overloading allows a class to have multiple methods with the same name, as long as their parameter types or number of parameters differ.

What is the primary benefit of using version control systems (like Git) in programming projects?

• To deploy web applications to a server.

• To compile source code into executable programs.

• To track changes, collaborate effectively, and revert to previous versions of code.

• To automatically optimize code for faster execution.

Answer explanation

Version control systems are essential for managing revisions, merging contributions, and maintaining a history of a codebase.

Consider two tables: `Orders` (OrderID, CustomerID, OrderDate) and `Customers` (CustomerID, CustomerName). Which type of SQL JOIN would return only the orders that have a matching customer?

• FULL OUTER JOIN

• INNER JOIN

• LEFT JOIN

• RIGHT JOIN

Answer explanation

INNER JOIN returns only the rows that have matching values in both tables.

Which SQL aggregate function is used to calculate the number of rows in a table?

• COUNT()

• MAX()

• SUM()

• AVG()

Answer explanation

COUNT() is used to count the number of rows that match a specified criterion.

An algorithm that repeatedly steps through the list, compares adjacent elements and swaps them if they are in the wrong order, is known as a:

• Binary Search

• Bubble Sort

• Merge Sort

• Quick Sort

Answer explanation

Bubble Sort performs repeated passes over the list, comparing and swapping adjacent elements, causing larger elements to 'bubble' to the end.

An algorithm with a time complexity of O(log n) means its execution time:

• Remains constant regardless of the input size.

• Grows exponentially with the input size.

• Grows very slowly, often halving the search space with each step.

• Grows linearly with the input size.

Answer explanation

Logarithmic complexity indicates that the time required increases very little as the input size grows significantly, common in binary search or tree operations.

What is the primary purpose of a Dynamic Host Configuration Protocol (DHCP) server?

• To filter network traffic based on security rules.

• To assign unique IP addresses and other network configuration parameters to devices automatically.

• To translate domain names into IP addresses.

• To connect different networks and route data packets between them.

Answer explanation

DHCP simplifies network administration by automating the process of IP address assignment.

What type of malware encrypts a victim's files and demands a payment (ransom) to restore access?

• Rootkit

• Spyware

• Ransomware

• Adware

Answer explanation

Ransomware is a type of malware that encrypts files and demands a ransom payment, usually in cryptocurrency, for their decryption.

A 'zero-day exploit' refers to:

• An attack that completely wipes out all data on a system, leaving 'zero' recoverable files.

• A security vulnerability that is unknown to the software vendor and for which no patch is available.

• A type of attack that requires zero interaction from the victim.

• A cyberattack that occurs on the first day a new software version is released.

Answer explanation

It means the developers have had 'zero days' to fix it since it became publicly known or exploited.