Mettl Coding Skills 4

Question 1

Which design pattern ensures only one instance of a class exists throughout an application?

Accepted Answer

Singleton

Answer

The Singleton pattern restricts instantiation to a single object and provides a global access point.

Question 2

What is the output of the following C code snippet: `int x = 5; printf("%d", x++);`?

Accepted Answer

5

Answer

Post-increment returns the original value before incrementing, so 5 is printed.

Question 3

Which of the following best describes a deadlock in concurrent programming?

Accepted Answer

Two or more processes each waiting for the other to release a resource

Answer

Deadlock occurs when processes circularly wait for resources held by each other, halting all progress.

Question 4

In object-oriented programming, what does 'encapsulation' mean?

Accepted Answer

Hiding internal state and exposing only necessary interfaces

Answer

Encapsulation bundles data and methods while restricting direct access to internal state.

Question 5

What is the result of evaluating `5 & 3` in most programming languages (bitwise AND)?

Accepted Answer

1

Answer

5 is 101 and 3 is 011 in binary; ANDing them yields 001, which equals 1.

Mettl Practice Test