Instructions

  • 1. Your final score will reflect your grasp of the concepts—approach each question with precision.
  • 2. Thoroughly review each solution before proceeding to ensure full understanding.
  • 3. Final results will be available after submission to provide insights into areas for further improvement.
  • 4. Maintain academic integrity—plagiarism undermines learning and professional growth.
  • 5. Once submitted, responses are final, so ensure you’re confident in your answers.
  • 6. These challenges are designed to test practical knowledge; apply your skills as you would in real-world scenarios.

All Problems

Question

Action

What is a callback function in JavaScript?

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What is the primary purpose of using a callback in JavaScript?

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Which of the following is an example of a callback function?

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When are callbacks typically executed in asynchronous code?

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Which of the following correctly demonstrates how to pass a callback function?

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What is the main disadvantage of using callbacks for handling asynchronous operations?

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How can "callback hell" be avoided in JavaScript?

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Which of the following will ensure a callback is executed after asynchronous code completes?

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What is the difference between a synchronous callback and an asynchronous callback?

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How are errors typically handled in callback-based asynchronous code?

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What is a callback function in JavaScript?

A function that is passed as an argument to another function and is executed after the completion of the function it is passed to.
A function that returns a promise.
A function that is only used in synchronous code.
A function that runs immediately after being defined.

What is the primary purpose of using a callback in JavaScript?

To handle asynchronous operations and execute code after a task is complete.
To convert synchronous code into asynchronous code.
To make code run faster.
To return a promise.

Which of the following is an example of a callback function?

setTimeout(function() { console.log("Hello"); }, 1000);

The function inside setTimeout.
The setTimeout function itself.
The console.log() function.
There is no callback function.

When are callbacks typically executed in asynchronous code?

After the current execution of the call stack is finished.
Immediately when the callback is defined.
Before the main function is executed.
After the event loop finishes.

Which of the following correctly demonstrates how to pass a callback function?

function processData(data, callback) { // Some code callback(data); } processData("Hello", function(result) { console.log(result); });

The second argument of processData is the callback function.
The first argument of processData is the callback function.
processData does not accept a callback.
callback is not a valid argument.

What is the main disadvantage of using callbacks for handling asynchronous operations?

It leads to "callback hell," making code harder to read and maintain.
Callbacks are too slow.
Callbacks can only be used in synchronous functions.
Callbacks make code run in parallel.

How can "callback hell" be avoided in JavaScript?

By using promises or async/await instead of nested callbacks.
By using more callbacks in the code.
By using only synchronous code.
By removing the event loop from the execution process.

Which of the following will ensure a callback is executed after asynchronous code completes?

Call the callback inside the asynchronous function, after the operation completes.
Call the callback before the asynchronous operation.
Use await instead of a callback.
Use a synchronous function instead of a callback.

What is the difference between a synchronous callback and an asynchronous callback?

A synchronous callback must return a value, while an asynchronous callback does not.
A synchronous callback runs in the event loop, while an asynchronous callback does not.
A synchronous callback is slower than an asynchronous callback.
A synchronous callback is executed immediately, whereas an asynchronous callback is executed after the current event loop finishes.

How are errors typically handled in callback-based asynchronous code?

By throwing an exception inside the callback.
By passing an error object as the first argument to the callback.
By using try...catch inside the callback function.
Errors cannot be handled in callbacks.