The Top C++ Interview Questions in 2020

As a hopeful C++ programmer, you’ve probably had to answer all kinds of questions about your skills, including too many questions about the differences between programming languages. If you intend to sit for job interviews, you can plan on getting a lot more questions about the language and how to use it. Knowing the most common C++ interview questions and answers will help you blow away the competition and get offered the top coding gigs.

Our article will help you get the information you need to take on any job interview with confidence after graduating from a C++ online course or bootcamp. We expose you to the sorts of questions and answers that you’ll find in any interview for a C++ position, regardless of the field or business sector. Our guide can help you prepare a study regimen to build a solid foundation and set you on a path to career success.

Explain References and Pointers

Hiring managers have a tough and thankless job—they have lots of people to interview, including you. They don’t want to waste time with candidates who don’t have what it takes. That’s why you’re likely to get a few tough questions at the top of the interview. These questions will be an initial bar you have to clear—if you can answer a question comparing languages or, within C++ itself, pointers and references, the manager will consider you worth a closer look. Better be ready with an answer.

It’s a good idea to look at intended use as a means to answer this question. Both references and pointers modify local function variables within a larger function, and you can use either to avoid copying large objects in arguments to functions or when returned from functions. However, references are both less powerful and less risky. You can’t reseat a reference once you deploy it, but it’s much less likely to refer to an invalid location than a poorly placed pointer.

What’s the Difference Between “While” and “Do While” Loops?

Whether you’re applying to be a business developer for an enterprise firm, a web developer for a startup, or a one-person-band for game development, you’ll have to master loops. Loops are essential parts of programs and reduce waste and overhead. A well-designed program is a series of loops, and hiring managers will want you to prove your mastery of them. Plan on explaining the difference between “do while” and “while” loops, for starters.

The big difference between these loop types is the placement of the terminating condition. A “while” loop places termination at the beginning of the loop: if the condition is met, the loop exits. However, a “do while” loop places the terminating condition at the end, thereby requiring at least one iteration before termination. This is a crucial difference between the two that dictates their use within your application.

Let’s Talk About Default Parameters

Expect to get a whole bunch of words thrown at you during your interview—and have a definition ready for each one. Much of the interview will look at your general knowledge and understanding of your craft. You’ll probably see some targeted problem-solving challenges, but explaining the building blocks of your profession will get you through most of the interview. Be ready to define default parameters, for example.

When you declare a function, you automatically assign every value to each parameter. That way, you don’t have to define each parameter every time you need it. If you leave the parameter blank, you use the default value. You only change the value when you assign a specific one to a parameter. It’s a huge time saver, a big part of modern programming, and a definition that you should be able to rattle off without hesitation. 

Storage Classes? You Betcha

As part of your work in C++, you’re going to deal with a ton of different storage classes. Storage classes are key parts of your code, and you should be ready to explain them in detail when asked. And you’re going to be asked about them, most likely. Getting your storage classes down cold and being able to talk about them confidently will go a long way toward securing your new job.

In the overall structure of your program, storage classes exist to define the scope and life of symbols, such as functions and variables. Want to make sure a variable does what you need it to do and then vanish? Use the right storage class. C++ has five storage classes: static, auto, extern, mutable, and register. Rattle this information off to your hiring manager when asked to get rewarded with an impressed nod. 

And there you go, friends and neighbors. C++ jobs pay well and offer a rewarding challenge to hopeful programmers. However, the best C++ gigs require you to make it through a tough interview process. Our guide helps you prepare for your interview and shows you some of the most common C++ interview questions and answers. With our assistance, you’ll be ready for anything the hiring manager brings to the table and can look forward to a fantastic career.