JavaScript (Coding): Debugging Test

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The JavaScript (Coding): Debugging Test evaluates a candidate's ability to identify and correct errors in JavaScript code. It covers key JavaScript concepts such as variable scope functions loops error handling and debugging techniques. The test includes MCQs and coding questions to assess problem-solving and debugging skills ensuring candidates can effectively troubleshoot and optimize JavaScript code.

Covered skills:

Variable Scope
Functions
Loops
Conditional Statements
Error Handling
Debugging Techniques
Object Manipulation
Array Methods
Asynchronous Programming
Event Handling
DOM Manipulation
Promises

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About the JavaScript (Coding): Debugging Assessment Test

The JavaScript (Coding): Debugging Test helps recruiters and hiring managers identify qualified candidates from a pool of resumes, and helps in taking objective hiring decisions. It reduces the administrative overhead of interviewing too many candidates and saves time by filtering out unqualified candidates at the first step of the hiring process.

The test screens for the following skills that hiring managers look for in candidates:

Proficient in using and manipulating JavaScript variables across different scopes.
Skilled in implementing and invoking functions effectively for various tasks.
Capable of efficiently employing control structures like loops and conditional statements.
Able to identify, handle, and debug errors to ensure smooth code execution.
Adept at applying debugging techniques to troubleshoot and fix code issues.
Experienced in manipulating objects and understanding object-oriented principles.
Competent in utilizing array methods to perform operations on data collections.
Knowledgeable in asynchronous programming techniques including callbacks, promises, and async/await.
Experienced in handling JavaScript events to create interactive web applications.
Skilled at manipulating the DOM to dynamically modify web page content.
Able to work with promises for managing asynchronous tasks within JavaScript.
Sound understanding of JavaScript's inherent capabilities and APIs.

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Non-googleable questions

We have a very high focus on the quality of questions that test for on-the-job skills. Every question is non-googleable and we have a very high bar for the level of subject matter experts we onboard to create these questions. We have crawlers to check if any of the questions are leaked online. If/ when a question gets leaked, we get an alert. We change the question for you & let you know.

How we design questions

These are just a small sample from our library of 15,000+ questions. The actual questions on this JavaScript (Coding): Debugging Test will be non-googleable.

🧐 Question
Medium Async Await Promises Promises Async-Await Asynchronous Programming	Solve
What will the following code output? A: 24 after 5 seconds and after another 5 seconds, another 24 B: 24 followed by another 24 immediately C: 24 immediately and another 24 after 5 seconds D: After 5 seconds, 24 and 24 E: Undefined F: NaN G: None of these
Medium Bitcoin prices Axios Promises	Solve
Review the following JavaScript code and pick the correct options: Assume that the API returns a successful 200 response code and a JSON object as the response body. What would the value of ‘a’ be after the code is executed?
Medium My Module Scope Javascript Es6 Closure	Solve
What will the output of the following JavaScript code be?
Medium Promise Resolve Promises Async-Await Code Analysis Syntax Understanding	Solve
What does the following code output?
Easy Throw, Try, Async Promises Async-Await Async/await	Solve
What does the following JS code output?

	🧐 Question	🔧 Skill
	Medium Async Await Promises Promises Async-Await Asynchronous Programming	2 mins JavaScript	Solve
What will the following code output? A: 24 after 5 seconds and after another 5 seconds, another 24 B: 24 followed by another 24 immediately C: 24 immediately and another 24 after 5 seconds D: After 5 seconds, 24 and 24 E: Undefined F: NaN G: None of these
	Medium Bitcoin prices Axios Promises	2 mins JavaScript	Solve
Review the following JavaScript code and pick the correct options: Assume that the API returns a successful 200 response code and a JSON object as the response body. What would the value of ‘a’ be after the code is executed?
	Medium My Module Scope Javascript Es6 Closure	2 mins JavaScript	Solve
What will the output of the following JavaScript code be?
	Medium Promise Resolve Promises Async-Await Code Analysis Syntax Understanding	2 mins JavaScript	Solve
What does the following code output?
	Easy Throw, Try, Async Promises Async-Await Async/await	2 mins JavaScript	Solve
What does the following JS code output?

	🧐 Question	🔧 Skill	💪 Difficulty	⌛ Time
	Async Await Promises Promises Async-Await Asynchronous Programming	JavaScript	Medium	2 mins	Solve
What will the following code output? A: 24 after 5 seconds and after another 5 seconds, another 24 B: 24 followed by another 24 immediately C: 24 immediately and another 24 after 5 seconds D: After 5 seconds, 24 and 24 E: Undefined F: NaN G: None of these
	Bitcoin prices Axios Promises	JavaScript	Medium	2 mins	Solve
Review the following JavaScript code and pick the correct options: Assume that the API returns a successful 200 response code and a JSON object as the response body. What would the value of ‘a’ be after the code is executed?
	My Module Scope Javascript Es6 Closure	JavaScript	Medium	2 mins	Solve
What will the output of the following JavaScript code be?
	Promise Resolve Promises Async-Await Code Analysis Syntax Understanding	JavaScript	Medium	2 mins	Solve
What does the following code output?
	Throw, Try, Async Promises Async-Await Async/await	JavaScript	Easy	2 mins	Solve
What does the following JS code output?

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Why you should use Pre-employment JavaScript (Coding): Debugging Test?

The JavaScript (Coding): Debugging Test makes use of scenario-based questions to test for on-the-job skills as opposed to theoretical knowledge, ensuring that candidates who do well on this screening test have the relavant skills. The questions are designed to covered following on-the-job aspects:

Identifying and fixing syntax errors in JavaScript
Debugging variable scope issues in code
Troubleshooting function-related problems
Resolving issues with loops and iterations
Debugging conditional statements and logic
Implementing proper error handling techniques
Using browser developer tools for debugging
Manipulating objects and their properties
Applying array methods to solve problems
Debugging asynchronous code and callbacks

Once the test is sent to a candidate, the candidate receives a link in email to take the test. For each candidate, you will receive a detailed report with skills breakdown and benchmarks to shortlist the top candidates from your pool.

What topics are covered in the JavaScript (Coding): Debugging Test?

Variable Scope: Understanding variable scope in JavaScript is critical to avoiding unintended side effects and bugs. This skill encompasses knowledge of local, global, block, and lexical scope. Proper scope management is essential for creating maintainable and predictable code.

Functions: Functions are the building blocks of modular and reusable code in JavaScript. Mastery of functions includes understanding function declarations, expressions, arrow functions, and anonymity. This skill is also crucial for implementing callback mechanisms and higher-order functions.

Loops: Loops are fundamental for iterating over collections and performing repetitive tasks efficiently. This includes understanding for, while, and do-while loops, as well as newer constructs like for...of and for...in. Efficient use of loops impacts algorithm performance and code readability.

Conditional Statements: Conditional statements allow for decision-making in code based on boolean conditions. Proficiency in if-else, switch-case, and ternary operators is vital for implementing complex logical flows. This skill ensures that code can respond dynamically to varying inputs and states.

Error Handling: Error handling is paramount for building robust applications that can gracefully manage exceptions and unforeseen issues. Knowledge of try-catch blocks, throw statements, and custom error objects is included. Effective error handling leads to better user experience and easier bug tracing.

Debugging Techniques: Debugging is an essential skill for identifying and fixing issues in code. Techniques include using console methods, breakpoints, step-through debugging, and profiling. Proficiency in debugging is critical for reducing development time and ensuring code reliability.

Object Manipulation: Object manipulation involves creating, modifying, and accessing objects and their properties. This skill covers the use of methods like Object.assign, Object.keys, and object destructuring. Understanding object manipulation is key for handling complex data structures and state management.

Array Methods: Array methods are powerful tools for array manipulation and transformation. This includes methods like map, filter, reduce, and spread operator. Mastery of these methods is crucial for writing clean, efficient, and expressive code.

Asynchronous Programming: Asynchronous programming allows for non-blocking execution of code, enabling smoother user experiences. This skill includes knowledge of callbacks, async/await, and event loops. Understanding asynchronous programming is vital for responsive application design.

Event Handling: Event handling involves capturing and responding to user and system events. This skill covers addEventListener, event propagation, and custom events. Proficiency in event handling is crucial for creating interactive web applications.

DOM Manipulation: DOM manipulation involves interacting with and updating the Document Object Model. This includes methods such as querySelector, appendChild, and innerHTML. Efficient DOM manipulation is necessary for dynamic content rendering and user interactions.

Promises: Promises provide a cleaner, more readable approach to handling asynchronous operations compared to callbacks. Mastery of Promises involves understanding then, catch, and finally methods. Promises are essential for managing asynchronous flows and error handling more gracefully.

Full list of covered topics

The actual topics of the questions in the final test will depend on your job description and requirements. However, here's a list of topics you can expect the questions for JavaScript (Coding): Debugging Test to be based on.

Variables

Variable Scope

Let

Const

Functions

Function Expressions

Arrow Functions

Recursion

Loops

For Loop

While Loop

Do-While Loop

Conditional Statements

If Statements

Switch Statements

Error Handling

Try Catch

Throw

Finally

Debugging Techniques

Console Log

Breakpoints

Debugger Keyword

Object Manipulation

Object Creation

Object Methods

Array Methods

ForEach

Map

Filter

Reduce

Asynchronous Programming

Callbacks

Promises

Async/Await

Event Handling

Event Listeners

Event Delegation

Event Propagation

DOM Manipulation

Document

QuerySelector

CreateElement

AppendChild

InnerHTML

Event Handling

Event Listeners

Event Bubbling

Event Capturing

Promises

Promise.all

Promise.race

Promise.resolve

Promise.reject

Modules

Export

Import

ES6

Template Literals

Destructuring

Rest Parameter

Spread Operator

Defaults

Hoisting

IIFE

Strict Mode

Closure

Prototype

Inheritance

Async Function

Fetch API

JSON

LocalStorage

SessionStorage

What roles can I use the JavaScript (Coding): Debugging Test for?

Frontend Developer
JavaScript Developer
Full Stack Developer
Web Developer
Software Engineer
Junior Developer
Backend Developer
Application Developer
UI Developer
Tech Lead

How is the JavaScript (Coding): Debugging Test customized for senior candidates?

For intermediate/ experienced candidates, we customize the assessment questions to include advanced topics and increase the difficulty level of the questions. This might include adding questions on topics like

Resolving issues with event handling in JavaScript
Debugging DOM manipulation and updates
Troubleshooting Promise-related code
Optimizing JavaScript code for performance
Debugging closures and lexical scoping
Resolving issues with prototype inheritance
Debugging complex data structures and algorithms
Troubleshooting memory leaks in JavaScript
Debugging cross-browser compatibility issues
Resolving race conditions in asynchronous code

The coding question for experienced candidates will be of a higher difficulty level to evaluate more hands-on experience.

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Have questions about the JavaScript (Coding): Debugging Hiring Test?

What is JavaScript (Coding): Debugging Test?

The JavaScript (Coding): Debugging Test evaluates a candidate's ability to identify and fix bugs in JavaScript code. Recruiters use it to ensure candidates possess strong debugging skills, which are crucial for developing robust and error-free applications.

Can I combine JavaScript (Coding): Debugging Test with JavaScript & NodeJS questions?

Yes, you can combine multiple skills into a single custom test. For more details on how we assess JavaScript & NodeJS skills, check out our JavaScript, NodeJS & React Test.

What topics are covered in the JavaScript (Coding): Debugging Test?

The test covers topics such as Variable Scope, Functions, Loops, Conditional Statements, Error Handling, Debugging Techniques, Object Manipulation, Array Methods, Asynchronous Programming, Event Handling, DOM Manipulation, and Promises.

How to use JavaScript (Coding): Debugging Test in my hiring process?

Use the test as a pre-screening tool early in your recruitment process. Add a link to the assessment in your job post or invite candidates by email. This helps identify skilled candidates earlier.

Can I test JavaScript and HTML/CSS together in a test?

Yes, you can test both JavaScript and HTML/CSS together. It's recommended for a more comprehensive frontend assessment. For more details, check out our JavaScript & HTML/CSS Test.

What are the main Frontend Developer tests?

Can I combine multiple skills into one custom assessment?

Yes, absolutely. Custom assessments are set up based on your job description, and will include questions on all must-have skills you specify. Here's a quick guide on how you can request a custom test.

Do you have any anti-cheating or proctoring features in place?

We have the following anti-cheating features in place:

Non-googleable questions
IP proctoring
Screen proctoring
Web proctoring
Webcam proctoring
Plagiarism detection
Secure browser
Copy paste protection

Read more about the proctoring features.

How do I interpret test scores?

The primary thing to keep in mind is that an assessment is an elimination tool, not a selection tool. A skills assessment is optimized to help you eliminate candidates who are not technically qualified for the role, it is not optimized to help you find the best candidate for the role. So the ideal way to use an assessment is to decide a threshold score (typically 55%, we help you benchmark) and invite all candidates who score above the threshold for the next rounds of interview.

What experience level can I use this test for?

Each Adaface assessment is customized to your job description/ ideal candidate persona (our subject matter experts will pick the right questions for your assessment from our library of 10000+ questions). This assessment can be customized for any experience level.

Does every candidate get the same questions?

Yes, it makes it much easier for you to compare candidates. Options for MCQ questions and the order of questions are randomized. We have anti-cheating/ proctoring features in place. In our enterprise plan, we also have the option to create multiple versions of the same assessment with questions of similar difficulty levels.

I'm a candidate. Can I try a practice test?

No. Unfortunately, we do not support practice tests at the moment. However, you can use our sample questions for practice.

What is the cost of using this test?

You can check out our pricing plans.

Can I get a free trial?

Yes, you can sign up for free and preview this test.

I just moved to a paid plan. How can I request a custom assessment?

Here is a quick guide on how to request a custom assessment on Adaface.

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Along with scorecards that report the performance of the candidate in detail, you also receive a comparative analysis against the company average and industry standards.

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