Node.js Test Upwork Answers 2021

Upwork Node.js Test Answers 2021

1. Which Node.js module can be used to get the IP address of the server the program is running on?

Answers: 

  • util
  • os dns
  • net

2. What does the following code do? var http = require(‘http’); var fs = require(‘fs’); var file = fs.createWriteStream(“file.png”); var request = http.get(“http://path/to/file.png”, function(response) { response.pipe(file); });

Answers: 

  • It creates an HTTP GET request and pipes its response into a writeable file stream.
  • It creates an HTTP GET request, and synchronously pipes its response into a writeable file stream.
  • It creates an HTTP POST request and pipes its response into a readable file stream.
  • It creates an HTTP POST request and pipes its response into a writeable file stream.

3. Which of the following methods can be used to write a file in Node.js?

Answers: 

  • fs.write()
  • fs.writeFile()
  • fs.createWriteStream()
  • fs.writeStream()

4. Which of the following methods will print to the console without a trailing new line?

Answers: 

  • process.stdout.print()
  • console.error()
  • console.log()
  • process.stdout.write()

5. Which of the following statements is true about the process object in Node.js?

Answers: 

  • It is a local object.
  • It is an instance of the events.EventEmitter class.
  • The process.exit(1) method ends the process with a “success” code.
  • “process.stderr” and “process.stdout” are non-blocking if they refer to regular files or TTY file descriptors.

6. Which of the following will synchronously check if a file/directory exists?

Answers: 

  • fs.exists()
  • fs.existsSync()
  • fs.checkFileSync()
  • fs.checkDirSync()

7. Which of the following methods can be used to read the contents of a directory?

Answers: 

  • fs.readdir()
  • fs.readdirSync()
  • fs.readDirectory()
  • fs.readdirAsync()

8. Which of the following console commands will update all installed global packages to the latest available versions?

Answers: 

  • npm upgrade -g
  • npm install -uga
  • npm update -g
  • npm version –install-latest

9. Which of the following statements are true about the child_process module in Node.js?

Answers: 

  • It is not possible to stream data through a child process’ stdin, stdout, and stderr in a fully non-blocking way.
  • Child processes always have two streams associated with them.
  • “require(‘child_process’).spawn()” can be used to create a child process.
  • “require(‘child_process’).fork()” can be used to create a child process.

10. Which array contains the command line arguments in Node.js?

Answers: 

  • process.argv
  • args.argv
  • arguments.argv
  • env.argv

11. Which of the following will copy a file in Node.js?

Answers: 

  • var fs = require(‘fs’); fs.createReadStream(‘test.file’).pipe(fs.createWriteStream(‘newFile.file’));
  • var fs = require(‘fs’); fs.createReadBuffer(‘test.file’).pipe(fs.createWriteBuffer(‘newFile.file’));
  • var fs = require(‘file’); fs.createFileReader(‘test.file’).pipe(fs.createFileWriter(‘newFile.file’));
  • var fs = require(‘fs’); fs.createReadBuffer(‘test.file’).stream(fs.createWriteBuffer(‘newFile.file’));

12. Which of the following statements are true about the module.exports object in Node.js?

Answers: 

  • It is the object that gets returned from a require() call.
  • It can be assigned in a callback.
  • Assigning an export object to module.exports will rebind the local exports variable.
  • None of these.

13. Which of the following will open a file, then read its contents one line at a time?

Answers: 

  • fs.readFileStream()
  • fs.readFile()
  • fs.createReadStream()
  • fs.createFileStream()

14. Which of the following NPM commands will install both dependencies and devDependencies of a given project?

Answers: 

  • npm install
  • npm install –dev
  • npm install –production
  • None of these

15. Which of the following statements is true about the console Object in Node.js?

Answers: 

  • “console.log” can take only a single argument.
  • “console.log” prints to stdout without a newline.
  • Its functions are synchronous when the destination is a terminal or a file, and and asynchronous when it’s a pipe.
  • Its functions are asynchronous when the destination is a terminal or a file, and and synchronous when it’s a pipe.

16. What does the following command do? npm view <package-name> version

Answers: 

  • It shows the version of the package installed globally.
  • It shows the version of the package installed locally.
  • It shows the version of the package that is cached.
  • It shows the latest version of the package that is available.

17. Which of the following can be used to get the currently running script’s path in Node.js?

Answers:  _

  • _filename
  • os.tmpdir()
  • path.dirname()
  • path.basename()

18. Which of the following can be used to access the environment variable, “ENV_VARIABLE” in Node.js?

Answers: 

  • process.env.ENV_VARIABLE
  • process.argv.ENV_VARIABLE
  • process.env.var.ENV_VARIABLE
  • process.environment.ENV_VARIABLE

19. What does process.argv[1] contain?

Answers: 

node

The file path of the JavaScript file.

The first command line argument.

The second command line argument.

20. Which of the following command-line arguments to “npm install” will allow an NPM package’s binaries to be run outside the project folder?

Answers: 

  • -g
  • –global
  • -l
  • –link