Mettl Fundamental Coding Skills 4

Question 1

What is a null pointer dereference?

Accepted Answer

Accessing memory at address zero or an uninitialized pointer

Answer

Dereferencing a null pointer attempts to access memory at an invalid address, usually causing a runtime crash.

Question 2

Which of the following is an example of a syntax error?

Accepted Answer

Missing a closing parenthesis in code

Answer

A missing closing parenthesis violates the grammar rules of the language, making it a syntax error caught at compile/parse time.

Question 3

What does the following pseudocode do? `for i from 1 to n: sum = sum + i`

Accepted Answer

Computes the sum of integers from 1 to n

Answer

The loop accumulates each integer from 1 to n into `sum`, computing the total sum of that range.

Question 4

What is the difference between `==` and `===` in JavaScript?

Accepted Answer

`==` checks value only; `===` checks value and type

Answer

`==` performs type coercion before comparing, while `===` (strict equality) requires both value and type to match.

Question 5

Which of the following best describes a binary search algorithm?

Accepted Answer

Searches by repeatedly halving the search interval on a sorted array

Answer

Binary search works on sorted arrays by comparing the target to the middle element and eliminating half the remaining elements each step.

Mettl Practice Test