Node.js Online Quiz

Following quiz provides Multiple Choice Questions (MCQs) related to Node.js Framework. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.

Q 1 - All APIs of Node.JS are.

A - Asynchronous

B - Synchronous

C - Both of the above.

D - None of the above.

Answer : A

Explanation

All APIs of Node.js library are aynchronous that is non-blocking.

Q 2 -What npm stands for?

A - Node Package Manager

B - Node Project Manager

C - New Project Manager

D - New Package Manager

Answer : A

Explanation

npm stands for Node Package Manager.

Q 3 - Which of the following is true with respect to Node.

A - Every API of Node js are asynchronous.

B - Node being a single thread, and uses async function calls to maintain the concurrency.

C - Node thread keeps an event loop and whenever any task get completed, it fires the corresponding event which signals the event listener function to get executed.

D - All of the above.

Answer : D

Explanation

Node js is a single threaded application but it support concurrency via concept of event and callbacks. As every API of Node js are asynchronous and being a single thread, it uses async function calls to maintain the concurrency. Node uses observer pattern. Node thread keeps an event loop and whenever any task get completed, it fires the corresponding event which signals the event listener function to get executed.

Q 4 - Which method of fs module is used to read a file?

A - fs.open(path, flags[, mode], callback)

B - fs.openFile(path, flags[, mode], callback)

C - fs.openPath(path, flags[, mode], callback)

D - fs.read(fd, buffer, offset, length, position, callback)

Answer : D

Explanation

fs.read(fd, buffer, offset, length, position, callback) is the method which is used to read a file.

Q 5 - Which method of fs module is used to truncate a file?

A - fs.delete(fd, len, callback)

B - fs.remove(fd, len, callback)

C - fs.ftruncate(fd, len, callback)

D - None of the above.

Answer : C

Explanation

fs.ftruncate(fd, len, callback) is the method which is used to truncate a file.

Q 6 - Which of the following code prints memory usage?

A - console.log(process.memoryUsage());

B - console.log('Current version: ' + process.memory());

C - console.log('Current version: ' + process.getMemory());

D - None of the above.

Answer : A

Explanation

process.memoryUsage() can be used to get the memory usage.

Q 7 - Which of the following code print the total free memory of operating system?

A - console.log('free memory : ' + os.freemem() + " bytes.");

B - console.log('free memory : ' + os.freemem + " bytes.");

C - console.log('free memory : ' + os.getFreeMemory() + " bytes.");

D - None of the above.

Answer : A

Explanation

os.freemem() returns the free amount of system memory in bytes.

Q 8 - Which of the following stands true for dns.lookup(hostname[, options], callback) method?

A - Resolves a hostname (e.g. 'google.com') into the first found A (IPv4) or AAAA (IPv6) record.

B - If options is not provided, then IP v4 and v6 addresses are both valid. If options is an integer, then it must be 4 or 6.

C - Both of the above.

D - None of the above.

Answer : C

Explanation

dns.lookup(hostname[, options], callback) resolves a hostname (e.g. 'google.com') into the first found A (IPv4) or AAAA (IPv6) record. options can be an object or integer. If options is not provided, then IP v4 and v6 addresses are both valid. If options is an integer, then it must be 4 or 6.

Q 9 - Can we create child processes in Node applications.

A - true

B - false

Answer : A

Explanation

Node facilitates creation of child processes to leverage parallel processing on multi-core cpu based systems.

Q 10 - Which of the following is true about RESTful webservices?

A - Webservices based on REST Architecture are known as RESTful web services.

B - Webservices uses HTTP methods to implement the concept of REST architecture.

C - Both of the above.

D - None of the above.

Answer : C

Explanation

Webservices based on REST Architecture are known as RESTful web services. These webservices uses HTTP methods to implement the concept of REST architecture.

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