CIW JavaScript Specialist 5

Question 1

What is the purpose of the JavaScript prototype chain?

Accepted Answer

To enable objects to inherit properties and methods from other objects

Answer

The prototype chain is JavaScript's inheritance mechanism, allowing objects to access properties and methods defined on their prototype objects.

Question 2

Which method of the Fetch API is used to parse a response body as JSON?

Accepted Answer

response.json()

Answer

response.json() reads the Response body stream and returns a Promise that resolves with the result of parsing it as JSON.

Question 3

What does the JavaScript 'use strict' directive do?

Accepted Answer

Enforces stricter parsing rules that catch common coding mistakes and prevent unsafe actions

Answer

'use strict' enables strict mode, which catches silent errors (like using undeclared variables) by throwing exceptions instead.

Question 4

In JavaScript, what is a callback function?

Accepted Answer

A function passed as an argument to another function and invoked after an operation completes

Answer

A callback function is passed into another function as an argument and is executed at a later point, often after an asynchronous operation completes.

Question 5

Which CSS manipulation approach is preferred in modern JavaScript to add or remove a class on an element?

Accepted Answer

element.classList.add() / element.classList.remove()

Answer

element.classList provides add(), remove(), toggle(), and contains() methods for cleanly managing an element's class list without overwriting existing classes.

CIW - Certified Internet Web Professional Practice Test

CIW - Certified Internet Web Professional Practice Test

CIW JavaScript Specialist 5