Mettl Coding Skills 3

Question 1

Which of the following correctly describes a hash collision?

Accepted Answer

Two different keys produce the same hash value

Answer

A collision occurs when two distinct keys hash to the same index in the table.

Question 2

What is the worst-case space complexity of recursive quicksort due to call stack usage?

Accepted Answer

O(n)

Answer

In the worst case (already sorted input), quicksort recurses n times, using O(n) stack space.

Question 3

In Java, which keyword prevents a method from being overridden in a subclass?

Accepted Answer

final

Answer

Declaring a method 'final' prevents subclasses from overriding it.

Question 4

What does a REST API use to indicate that a resource was successfully created?

Accepted Answer

HTTP 201 Created

Answer

HTTP 201 Created is the standard response for a successful POST that creates a new resource.

Question 5

Which of the following is NOT a valid way to declare a variable in JavaScript (ES6+)?

Accepted Answer

def x = 5;

Answer

'def' is used in Python, not JavaScript; valid JS declarations use var, let, or const.

Mettl Practice Test