Javascript

JavaScript Mastery Quiz

Test your knowledge of JavaScript and Node.js with this engaging quiz designed for enthusiasts and professionals alike. With 29 challenging questions, you'll discover how well you understand key concepts such as asynchronous programming, Promises, calls to external modules, and much more.

Whether you're preparing for a job interview or simply want to gauge your skills, this quiz is for you. Get ready to dive into:

Node.js Features
Asynchronous Programming
JavaScript Syntax
Modern JavaScript Practices

29 Questions7 MinutesCreated by CodingWizard543

In a Node program what does process.argv contain?

The version of Node being used

The command line arguments

The full path of the program

The name of the program

Mosh Hamedani compares an asynchronous program to a waiter in a restaurant who ...

Waits for one tables meal to be prepared before serving another table

Waits for all customers at a table to decide what they want before serving another table

Serves new tables while the meals for other tables are being prepared

Serves all tables at once

Serves the table with the most customers first

In Node, when you write a function in a JavaScript file where is it accessible by default?

Everywhere

In any file on the same server

In any file in the same folder

Only in the file where it is defined

According to Mosh Hamedani the best description of Node is:

A JavaScript framework

A JavaScript-related programming language

A JavaScript library

A JavaScript runtime environment

Node programs are ...

Single-threaded and non-blocking

Multi-threaded and non-blocking

Single-threaded and blocking

Multi-threaded and blocking

If you call a Node program by entering 'node app 4' how does the program access the value 4 passed in?

Process.argv[0]

Process.argv[3]

Process.argv[2]

Process.argv[1]

What is a Promise?

A synchronous version of a callback

An object that will be completed in the future

An error handler for a callback function

An asynchronous function

The keyword 'await' is used to ...

Indicate that a function is asynchronous

Return a Promise to the caller

Delay a function until more system resources are available

Wait for a Promise to resolve

Which of the following statements about callback functions is false?

It is returned by another function

It is called in the future

It is called by the system

It is passed to another function

Suppose a function, foo, returns a Promise. One way to get the data returned when the Promise resolves successfully is to write 'foo().then(function(data) { ... });' What is a more modern way of getting the data?

Async foo(data)

Data = await foo()

Foo(data.promise)

Data = fetch(foo())

Why is it a good idea to include a toJSON method in a JavaScript class?

To allow instances to be created with JSON.parse rather than the constructor

To allow JSON.stringify to work properly

To indicate that the class does not contain any non-standard data

To make it easy to display the data

When a section of code is described as 'callback hell', it means the code is difficult to understand because ...

It uses more callbacks than are required

Any callback is difficult to understand

The code will only work if the callbacks run in a certain order

It has nested callbacks

Function someFunc(x, y) { // do something } Now suppose that we call the function by writing someFunc(4). Which of the following is true?

Y will be ignored

The function will return an error message

X will contain 4 and y will be undefined

X and y will both contain 4

In a JavaScript class, how do you declare a 'get' function for a field called 'stuff' so that the function can be called on an instance, obj, by writing 'obj.stuff'?

Get stuff()

Get_stuff()

#getstuff()

GetStuff()

What will happen if you call an aysnchronous function but forget to write 'await' in front of it?

The program will run very slowly

The program will run normally but maybe not asynchronously

The program will not run

The program will hang indefinitely

What is the name for a string that specifies the location and name of a file, including the name of the file and any sub folders that need to be navigated - for example: "..\src\db\ConnectionManager.js"?

In a terminal session (command line), what is the command to display the contents of a file?

What is the acronym that represents the four fundamental database operations?

RAGU: Remove-Add-Get-Update

CRUD: Create-Read-Update-Delete

FADE: Fetch-Add-Delete-Edit

FAIR: Find-Alter-Insert-Remove

After you open a Mongo connection to a database, what else must you do before you can execute a query?

Set up a try/catch block to handle potential errors

Ensure that all other connections have been closed

Obtain a reference to a collection

Obtain a reference to a processing thread