MS Master of Computer Science 5

Question 1

Which design pattern ensures a class has only one instance and provides a global access point to it?

Accepted Answer

Singleton

Answer

The Singleton pattern restricts instantiation of a class to a single object and provides a static method to access that instance globally.

Question 2

What is the purpose of the 'volatile' keyword in Java or C?

Accepted Answer

To indicate a variable may be modified by multiple threads and disable caching/reordering optimizations

Answer

Declaring a variable volatile tells the compiler and CPU to always read/write it from main memory, preventing stale cached copies in multi-threaded code.

Question 3

In formal language theory, which class of languages is recognized by a pushdown automaton (PDA)?

Accepted Answer

Context-free languages

Answer

Pushdown automata recognize exactly the context-free languages; the stack gives them enough memory to match nested structures like parentheses.

Question 4

What does 'eventual consistency' mean in distributed databases?

Accepted Answer

If no new updates occur, all replicas will eventually converge to the same value

Answer

Eventual consistency guarantees that, given enough time without new updates, all replicas will return the same value — it does not guarantee immediate consistency.

Question 5

Which asymptotic notation describes a tight bound — both upper and lower — on an algorithm's growth rate?

Accepted Answer

Θ (Big-Theta)

Answer

Θ-notation (Big-Theta) means the algorithm's growth rate is sandwiched between constant multiples of a function from both above and below.

MS - Master of Science Practice Test

MS - Master of Science Practice Test

MS Master of Computer Science 5