Coding Interview Questions for Programmers

40 specialized coding interview questions to ask programmers.

Coding Interview Questions for Programmers

July 14th, 2020

When interviewing candidates for programming positions, it is best to use targeted coding interview questions to gauge the candidate's understanding and knowledge of coding procedures. The following interview questions have been carefully chosen to test candidates on language-specific criteria.

Coding Interview Questions PDF Download

Download this free PDF document with all the top coding interview questions to ask programmers.

Download Instant download. No email required.

Java Coding Interview Questions:

1. Can you tell me the differences between vectors and arrays?
Tests knowledge of data structures.

2. When would you use an abstract class?
Tests knowledge of object-orientated programming.

3. What is the finalize() method?
Tests efficient programming protocols.

4. Why would it be more secure to store sensitive user data in a character array rather than in a String?
Tests deep knowledge of Java programming.

5. Can you explain what is meant by inheritance?
Tests knowledge of object-orientated programming.

HTML Coding Interview Questions:

1. What is the advantage of collapsing white space in HTML?
Tests knowledge of HTML design and web layout.

2. How do you use an image map in HTML?
Tests knowledge of page links.

3. Is it possible to modify the attribute's value of the HTML tag dynamically?
Tests knowledge of HTML modification using alternate languages.

4. What is the role of meta tags in HTML?
Tests general coding knowledge of HTML.

5. Can you describe the common structure all HTML pages follow?
Tests detailed knowledge of webpage design.

Python Coding Interview Questions.

1. What is the significance of PEP 8 in relation to Python?
Tests knowledge of Python style guidelines.

2. What is meant by scope resolution in Python?
Tests knowledge of object functionality.

3. Can you name the different tools that are used to check bugs in Python?
Tests knowledge of static analysis tools.

4. Why are namespaces used in Python?
Tests knowledge of scope and objects.

5. How do you convert a number to a string in Python?
Tests knowledge of Python code functions.

Ruby Coding Interview Questions:

1. What is RubyGems?
Reveals knowledge of Ruby libraries.

2. Can you name some of the features of Ruby?
Tests general knowledge of Ruby language.

3. In what way are Ruby and Python similar?
Tests knowledge backend languages and their functions.

4. What is the difference between include and extend in Ruby?
Tests knowledge of module methods.

5. Can you name some of the operators used in Ruby and their functions?
Tests knowledge of Ruby operators.

JavaScript Coding Interview Questions:

1. Can you explain the difference between Java and JavaScript?
Tests knowledge of programming languages.

2. What is the function of timers in JavaScript?
Tests knowledge of basic JavaScript functions.

3. How would you change the style/class of an element in JavaScript?
Tests knowledge of class entries.

4. What are the two ways to read and write a file using JavaScript?
Tests knowledge of file writing.

5. What are the names and functions of the looping structures in JavaScript?
Tests knowledge of looping structures.

PHP Coding Interview Questions:

1. What is the name of the scripting engine that powers PHP?
Tests general knowledge of PHP.

2. What are the main differences between PHP4 and PHP5?
Tests knowledge of the PHP language base.

3. What are the main error types in PHP?
Tests knowledge of error codes.

4. How many data types are there in PHP?
Tests knowledge of data values.

5. What is the easiest way to get a client's IP address using PHP?
Tests knowledge of scripting resources.

See our full list of PHP Developer interview questions.

.NET Coding Interview Questions:

1. Which scripting languages does the .NET Framework support?
Tests knowledge of .NET language capabilities.

2. Can you describe a simple way to execute unmanaged code?
Tests knowledge of .NET essential functions.

3. Can you name the different .NET assemblies and their functions?
Tests for knowledge of the resources required to build an application using .NET.

4. What is the function of the garbage collector in .NET?
Tests knowledge of standard coding procedures.

5. What is the difference between Stack and Heap?
Tests knowledge of stored values.

jQuery Coding Interview Questions:

1. What is the difference between JavaScript and jQuery?
Tests for knowledge of JavaScript libraries.

2. What is the use of css() method in jQuery?
Test knowledge of style properties.

3. What is the starting point of code execution in jQuery?
Tests for general jQuery coding knowledge.

4. What are the main advantages of using a CDN?
Tests for server knowledge.

5. What would you use the val() method for in jQuery?
Tests knowledge of element matching.

Tips for Interviewing Programmers:

If you are interviewing for a junior programming position, it is best to use simple exercises to test basic coding knowledge. For more senior positions, opt for a written assignment where you can see how the candidate approaches and resolves each problem with written code.

In many cases asking too many technical questions can overwhelm candidates, leading to skewed results. Unless you are also testing for candidates that can work under pressure, you should space technical questions with experienced-based ones.

FAQs:

How do you practice for a coding interview?

  • Write your code on a piece of paper and note your mistakes.
  • Test your theoretical knowledge with simulated scenarios.
  • Brush up on languages you are not familiar with.

How do you answer a coding interview question?

  • Think about the question before answering.
  • Use the whiteboard or paper to write down your answers.
  • Start over if necessary or keep talking until you have the answer.
  • Don't try and rush the answer. Getting it right is the most more important than speed.

What are some Python coding questions to ask in an interview?

  • What is the significance of PEP 8 in relation to Python?
  • What is meant by scope resolution in Python?
  • Can you name the different tools that are used to check bugs in Python?
  • Why are namespaces used in Python?
  • How do you convert a number to a string in Python?

Should you ask language-specific coding questions when interviewing a programmer?

Yes, while all programmers should have basic coding knowledge, code testing for specific languages is key when filling role-specific positions.