Preparing for a Tech Interview: Common C++ Interview Questions

Global Employability

If you have a technological background, you’re in luck! The tech industry has seen quite a paradigm shift and a lot of new opportunities are being created every day.

Table of contents:

  • What is C++ language used for?
  • C++ interview questions you should know

What is C++ language used for?

According to the TIOBE index, C++ is the fourth most popular language in the world! It is one of the few fundamental languages that still enjoy relevance in today’s world, even after 40 years since its inception!

C++ is used in many applications including building operating systems (Windows, macOS), developing games with high-quality graphics (game engines like Unreal Engine, Unity), managing databases (MySQL), designing IoT applications and controlling these devices, machine learning tools, AR/VR applications, search engines (Google, Firefox), telecommunications, and even in scientific research.

C++ interview questions you should know

When you apply to a role that predominantly makes use of C++ as its core technology, there are a few questions that you should be prepared to answer. Some of these C ++  interview questions are listed below to help you!

  • Do you prefer to use any particular online resources for helping you with your job?Usually, working in a development job does not mean that you will be writing your own piece of code. Most of the time, one will be referring to online resources to understand how things work or to learn about new concepts. An interviewer will ask you this to check whether you get your information from reliable sources or if your sources are sketchy.
  • What is a namespace?Namespaces create definite logical scopes within which identifiers can exist. Think of having two different functions with the same name, but have been defined in different libraries. The compiler can easily get confused. To avoid this, namespaces are used in C++, which was not introduced in C.
  • What are constructors and destructors?A constructor is a member function of a class that helps to initialize the objects that belong to this class. It has the same name as the class and does not have to be invoked explicitly.Destructors are automatically invoked functions that are used to remove the memory allocation for objects (basically freeing up space) whenever they go out of scope or are about to be destroyed.
  • What is a constant and how do you declare it?A constant is usually a variable whose values cannot be changed once it has been declared. To declare a variable as constant in C++, we use the “#define” preprocessor directive or the “const” keyword.
  • What is operator overloading?Operator overloading is the process of having operators (symbols for mathematical operations such as +,-,/, etc) function according to user-defined classes. For example, ‘+’ can be used for the addition of two numeric values as well as the concatenation of two strings! This is controlled by changing the data type of the variables involved.
  • How would you explain the concept of encapsulation to someone with a very limited background in tech?Encapsulation is the concept of bundling together data and the functions that are used to manipulate this data into one. It restricts access to objects that are “outside” the encapsulated class’ scope.The way this question is framed is to gauge your understanding of concepts rather than checking to see if you can give a memorized answer. By explaining the concept in a simple manner, the interviewer will gain insights into your method of thinking.
  • What is function overloading and function overriding?Function overloading is when two different functions have the same name but have different parameters, either in terms of the data type of the parameters or the number of parameters used.Function overriding is the concept of redefining a parent class by a child class. To understand this concept, one needs to know about inheritance.
  • What is inheritance?It is the concept of one class deriving the properties of another class. It is one of the most important concepts of object-oriented programming. For example, “animal” can be a superclass whose properties (methods such as limbs(), blood type(), etc) are inherited by subclasses such as reptiles, mammals, and others.

This is only a subset of the possible C++ interview questions that you could be asked. Keep visiting this space for part 2!

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