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About the test:

The C online test uses a range of MCQs and coding questions to evaluate candidates on their fundamental knowledge of C programming concepts, including data types, control statements, arrays, pointers, functions, and file handling. Additionally, the test assesses candidates' ability to work with dynamic memory allocation, structures, and advanced C programming concepts such as preprocessor directives and macros.

Covered skills:

  • C Programming
  • Operators
  • Functions
  • Strings
  • Structures and Unions
  • Variables and Data Types
  • Control Structures
  • Arrays
  • Pointers
  • File Handling

9 reasons why
9 reasons why

Adaface C Test is the most accurate way to shortlist Core C Developers

Reason #1

Tests for on-the-job skills

The C Online 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 C Programming language
  • Thorough understanding of variables and data types in C
  • Knowledge of different operators and their usage in C
  • Familiarity with control structures such as if-else and switch-case in C
  • Ability to write functions and understand their significance in C
  • Understanding of arrays and their manipulation in C
  • Knowledge of string manipulation in C
  • Proficient in working with pointers in C
  • Understanding of structures and unions in C
  • Familiarity with file handling in C
  • Ability to problem solve and write efficient code in C
Reason #2

No trick questions

no trick questions

Traditional assessment tools use trick questions and puzzles for the screening, which creates a lot of frustration among candidates about having to go through irrelevant screening assessments.

View sample questions

The main reason we started Adaface is that traditional pre-employment assessment platforms are not a fair way for companies to evaluate candidates. At Adaface, our mission is to help companies find great candidates by assessing on-the-job skills required for a role.

Why we started Adaface
Reason #3

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 10,000+ questions. The actual questions on this C Online Test will be non-googleable.

🧐 Question


Memory Allocation
Check the following three C functions:
Which among these will likely cause issues with pointers?


Pointers and Structs
What is the output of the following C code?


What is the output of the following C code?


Registration Queue
We want to register students for the next semester. All students have a receipt which shows the amount pending for the previous semester. A positive amount (or zero) represents that the student has paid extra fees, and a negative amount represents that they have pending fees to be paid. The students are in a queue for the registration. We want to arrange the students in a way such that the students who have a positive amount on the receipt get registered first as compared to the students who have a negative amount. We are given a queue in the form of an array containing the pending amount.
For example, if the initial queue is [20, 70, -40, 30, -10], then the final queue will be [20, 70, 30, -40, -10]. Note that the sequence of students should not be changed while arranging them unless required to meet the condition.
⚠️⚠️⚠️ Note:
- The first line of the input is the length of the array. The second line contains all the elements of the array.
- The input is already parsed into an array of "strings" and passed to a function. You will need to convert string to integer/number type inside the function.
- You need to "print" the final result (not return it) to pass the test cases.

For the example discussed above, the input will be:
20 70 -40 30 -10

Your code needs to print the following to the standard output:
20 70 30 -40 -10


Visitors Count
A manager hires a staff member to keep a record of the number of men, women, and children visiting the museum daily. The staff will note W if any women visit, M for men, and C for children. You need to write code that takes the string that represents the visits and prints the count of men, woman and children. The sequencing should be in decreasing order. 


Expected Output: 

‘W’ has the highest count, then ‘C’, then ‘M’. 
⚠️⚠️⚠️ Note:
- The input is already parsed and passed to a function.
- You need to "print" the final result (not return it) to pass the test cases.
- If the input is- “MMW”, then the expected output is "2M1W" since there is no ‘C’.
- If any of them have the same count, the output should follow this order - M, W, C.
🧐 Question🔧 Skill


Memory Allocation

2 mins



Pointers and Structs

2 mins




2 mins



Registration Queue

30 mins



Visitors Count

30 mins

🧐 Question🔧 Skill💪 Difficulty⌛ Time
Memory Allocation
Medium2 mins
Pointers and Structs
Medium2 mins
Medium2 mins
Registration Queue
Easy30 minsSolve
Visitors Count
Medium30 minsSolve
Reason #4

1200+ customers in 75 countries

customers in 75 countries

With Adaface, we were able to optimise our initial screening process by upwards of 75%, freeing up precious time for both hiring managers and our talent acquisition team alike!

Brandon Lee, Head of People, Love, Bonito

Reason #5

Designed for elimination, not selection

The most important thing while implementing the pre-employment C Online Test in your hiring process is that it is an elimination tool, not a selection tool. In other words: you want to use the test to eliminate the candidates who do poorly on the test, not to select the candidates who come out at the top. While they are super valuable, pre-employment tests do not paint the entire picture of a candidate’s abilities, knowledge, and motivations. Multiple easy questions are more predictive of a candidate's ability than fewer hard questions. Harder questions are often "trick" based questions, which do not provide any meaningful signal about the candidate's skillset.

Science behind Adaface tests
Reason #6

1 click candidate invites

Email invites: You can send candidates an email invite to the C Online Test from your dashboard by entering their email address.

Public link: You can create a public link for each test that you can share with candidates.

API or integrations: You can invite candidates directly from your ATS by using our pre-built integrations with popular ATS systems or building a custom integration with your in-house ATS.

invite candidates
Reason #7

Detailed scorecards & benchmarks

View sample scorecard
Reason #8

High completion rate

Adaface tests are conversational, low-stress, and take just 25-40 mins to complete.

This is why Adaface has the highest test-completion rate (86%), which is more than 2x better than traditional assessments.

test completion rate
Reason #9

Advanced Proctoring

Learn more

About the C Assessment Test

Why you should use Pre-employment C Online Test?

The C Online 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:

  • C programming skills including data types, variables, operators, control structures, functions, arrays, strings, pointers, structures, unions, and file handling
  • In-depth knowledge of C syntax and code structure
  • Ability to write efficient and optimized C code
  • Experience in debugging and troubleshooting C programs
  • Understanding of memory management in C
  • Proficiency in using C libraries and APIs
  • Expertise in working with multi-dimensional arrays in C
  • Understanding of file handling operations in C
  • Ability to implement complex algorithms in C
  • Experience with error handling and exception management in C

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 C Online Test?

  • C Programming

    C Programming is a programming language commonly used for system programming and low-level computer operations. It is essential to measure this skill in the test to assess a candidate's ability to write efficient and optimized code using C language.

  • Variables and Data Types

    Variables and Data Types are fundamental concepts in programming. This skill should be measured in the test to evaluate a candidate's knowledge of different variable types, their declaration, and their usage in C programming.

  • Operators

    Operators are symbols that perform specific operations on one or more operands. Measuring this skill in the test helps assess a candidate's understanding and proficiency in using arithmetic, relational, logical, and bitwise operators in C programming.

  • Control Structures

    Control Structures are statements that control the flow of execution in a program. This skill is measured in the test to evaluate a candidate's ability to construct and use conditional statements, loops, and branching structures to achieve desired program behavior.

  • Functions

    Functions are self-contained blocks of code that perform specific tasks. Measuring this skill in the test helps assess a candidate's understanding of function declaration, definition, invocation, parameters, return types, and their role in modular programming using C language.

  • Arrays

    Arrays are collections of similar data types stored in a contiguous memory location. This skill should be measured in the test to evaluate a candidate's knowledge of array declaration, initialization, accessing elements, and their applications in storing and manipulating a fixed number of values.

  • Strings

    Strings are sequences of characters in C programming. Measuring this skill in the test helps assess a candidate's understanding of string manipulation, handling, concatenation, comparison, and their usage in various applications involving text processing.

  • Pointers

    Pointers are variables that hold memory addresses of other variables. This skill is measured in the test to evaluate a candidate's knowledge of pointer declaration, arithmetic, dereferencing, dynamic memory allocation, and their importance in memory management and efficient data access in C programming.

  • Structures and Unions

    Structures and Unions are user-defined data types that allow combining different data types into a single entity. Measuring this skill in the test helps assess a candidate's understanding of creating and manipulating structures and unions, accessing their members, and their role in organizing and representing complex data in C programming.

  • File Handling

    File Handling involves performing operations on files, such as reading, writing, and modifying their contents. Measuring this skill in the test evaluates a candidate's knowledge of file handling functions, file opening modes, and their ability to perform file I/O operations in C programming.

  • 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 C Online Test to be based on.

    C Variables
    Primitive Data Types
    Type Conversion
    Arithmetic Operators
    Relational Operators
    Logical Operators
    Bitwise Operators
    Assignment Operators
    Conditional Statements
    Looping Statements
    Functions in C
    Arrays in C
    Strings in C
    Pointers in C
    Dynamic Memory Allocation
    Structures in C
    Unions in C
    File Input/Output in C
    Preprocessor Directives
    Error Handling
    Debugging Techniques
    Code Optimization
    Algorithmic Complexity
    Data Structures
    Memory Management
    Object-Oriented Programming Concepts in C
    Command Line Arguments
    Static Libraries
    Dynamic Libraries
    Coding Standards
    Testing and Debugging
    Integrated Development Environments (IDEs)
    Version Control Systems
    Secure Coding Practices
    Code Review
    Code Reusability
    Performance Analysis
    Error Handling and Exceptions
    Real-time Systems
    Embedded Systems
    Operating Systems Concepts
    Computer Organization and Architecture
    Data Representation
    Binary Number System
    Hexadecimal Number System
    ASCII Encoding
    Endian Conversion
    Character Encoding
    Firmware Development
    Low-Level Programming
    Software Development Life Cycle (SDLC)
    Agile Development
    Waterfall Model
    Spiral Model
    Prototyping Model
    Iterative Model

What roles can I use the C Online Test for?

  • Core C Developer
  • Software Engineer (C)
  • Embedded Systems Engineer
  • Game Developer
  • Network Engineer
  • Security Analyst

How is the C Online 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

  • Knowledge of object-oriented programming concepts in C
  • Familiarity with dynamic memory allocation in C
  • Proficiency in using bitwise operators in C
  • Understanding of recursion and recursive functions in C
  • Knowledge of pointers and their manipulation in C
  • Experience with handling strings and string manipulation in C
  • Ability to work with structures and unions in C
  • Understanding of input/output operations in C
  • Experience in implementing data structures in C
  • Knowledge of advanced topics such as function pointers and macros in C
  • Proficiency in using the preprocessor directives and conditional compilation in C

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

Singapore government logo

The hiring managers felt that through the technical questions that they asked during the panel interviews, they were able to tell which candidates had better scores, and differentiated with those who did not score as well. They are highly satisfied with the quality of candidates shortlisted with the Adaface screening.

reduction in screening time

C Hiring Test FAQs

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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40 min tests.
No trick questions.
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