Top 6 Most Common C++ Mistakes That You Must Avoid To Improve

C++ is a sophisticated language that is riddled with subtle traps for the unwary. There are nearly unlimited ways to muck things up. Ultimately, any compiler-detectable fault becomes irrelevant if it is handled properly, as it will be noticed and corrected before the programme exits development. At worst, a compiler-detectable error causes the programmer to lose time while he or she seeks a solution or workaround.

The most harmful faults are those that compilers do not catch. These faults are far less noticeable and can have serious effects such as inaccurate output, damaged data, and/or software crashes.

As a computer project grows in size, the complexity of the logic and the enormous number of possible pathways of execution can assist disguise these flaws, leading them to occur only seldom and making them particularly difficult to track down and debug.

Taking a C++ tutorial to learn c++ can help you become aware about these mistakes and not make the mistakes beginners make.

Here we will talk about the most common mistakes programmers make in C++.

What exactly is C++?

C++ is a versatile, object-oriented programming language that is extensively used in the software development industry. While C++ is related to C — its creator Bjarne Stroustrup coined the term ‘C with classes’ — the two languages have major differences, and C++ has grown independently.

Additionally, C++ is a foundational language for other programming languages such as Python.

Among the tasks of a C++ developer are the following:

  • Conducting studies on a variety of software applications and programmes to ascertain their potential for optimization and enhancement using C++.
  • They plan and build software and programmes while keeping the demands of their customers and users in mind, utilising their in-depth expertise in C++.
  • Ensure appropriate functioning of the software by testing, debugging, and, if required, updating the C++ script.

Common C++ Errors

As with other technologies, the language includes problems that need developers to focus more on quality development. These C language mistakes can result in degraded code quality and high maintenance costs. However, you can prevent these repercussions by exercising caution throughout C++ development.

Because both C and C++ languages have a common grammar, there is less potential for mistakes. The more you practice, the more familiar you get and chances of you making mistakes get reduced. Let’s have a look at some of the most often occurring C and C++ problems.

1. Errors in Syntax

Syntax mistakes are errors made by programmers when inputting code. C++ has some grammar rules, and when the syntax has any grammatical flaws, the computer has a difficult time ignoring them. It’s straightforward; computers adhere to certain grammatical rules and are incapable of comprehending anything else.

As you gain proficiency in C++, you become less prone to commit syntactic mistakes. When confronted with a syntax mistake, your cell phone may come in useful for obtaining immediate information about the current issue.

Syntax problems in your code may include:

  • Missing parentheses
  • Colons
  • Semicolons

2. Logical Errors

When everything appears to be performing flawlessly in the direction in which it was planned to function, yet the programme abruptly terminates, there is a logical flow fault. In this scenario, the programme you input is accurate, but it is failing to compile and execute the appropriate data or outcome.

A logical error would be designing code that returns the most recent employee joining information while you’re seeking for the oldest employee. In other words, when a software is created to do one function yet the requirement requires the exact opposite.

When you begin developing C++ code, consult with the project manager to ensure that everything is in order and that you are proceeding in the correct path. Cross-check to ensure that the reasoning you’re using is right.

3. Errors Occurring at Runtime

Runtime errors are errors that occur during the execution phase. It is likely that the code is executing normally prior to execution, on another device, and not on the server. The code may have been manipulated or performed in such a way that it generates a runtime error.

The most frequent type of error in C or C++ is the Division error, which is also one of the most difficult to discover because the compiler provides no indication of where the fault occurred. The Linker error is another type of runtime error that happens when the execution cannot be generated.

Ascertain that you have a responsive error reporting system in place to efficiently capture runtime issues. Using frameworks is a proven method for minimising runtime faults since the code may have been used earlier in another project. Thus, you may gain insight on the persisting issue and its resolution.

4. Arithmetic Errors

Similar to logical error, arithmetic error is a frequent occurrence in C++ and refers to mathematical mistakes. For instance, it is not feasible to divide by zero without causing an error or a glitch while conducting division computations.

In some situations, an arithmetic error can result in a logical error, and in extreme cases, it can result in a runtime error when dividing by zero. To prevent arithmetic mistakes, you may use functional tests that cover a wide variety of edge situations, such as negative numbers or zero.

Another technique to avoid math-related mistakes when coding in C is to verify the inputs to the functions. When a function is called with the incorrect input, the header file’s variable value is typically changed to something other than zero.

5. Virtual Destructor Ignored

This is a very common issue that results in memory leaks inside derived classes that have dynamic memory allocated. Virtual destructors are not always ideal, for example, when a class is not designed for inheritance, and its size and speed are critical. A virtual destructor or any other virtual function adds more data to the structure of a class, for example, a pointer to a virtual table, increasing the size of any instance of the class.

However, in the majority of circumstances, classes can be inherited even if they were not meant to be. As a result, it is a very good practice to include a virtual destructor when declaring a class. Otherwise, if a class must be devoid of virtual functions for performance reasons, it is a good practice to include a note within the class declaration file indicating that the class should not be inherited. One of the easiest ways to circumvent this issue is to utilise an IDE that permits the generation of virtual destructors during class development.

Additionally, classes/templates from the standard library are relevant to the subject. They are not inheritable and lack a virtual destructor. If we develop a new, improved string class that openly inherits from std::string, for example, there is a chance that it may be used wrongly with a pointer or reference to std::string, resulting in a memory leak.

To prevent such C++ concerns, a more secure method of reusing a standard library class/template is to utilise private inheritance or composition.

6. Utilization of Invalid Iterators and References

An entire book might be written on this subject. Each STL container has a unique set of circumstances under which it invalidates iterators and references. It is critical to keep these things in mind before doing any process. As with the prior C++ issue, this one can arise often in multithreaded systems, which is why synchronisation methods are essential to avoid it. As an illustration, consider the following sequential code:

From a logical standpoint, the code appears to be just OK. However, adding the second member to the vector may result in memory reallocation, rendering both the iterator and reference illegal and resulting in an access violation error in the final two lines.


A C++ Developer earns an average salary of Rs. 512,517.

C ++ is the main programming language today, and if you are a recent graduate pursuing this career path, you have a very bright future ahead of you. To secure your dream job and kick-start your career, follow these guidelines.

C++ is an extremely capable programming language. Indeed, many of the programmes you use on a daily basis and love were undoubtedly written in C++. C++ as a language provides the developer with enormous freedom, owing to some of the most sophisticated features found in object-oriented programming languages.

However, if not handled appropriately, these sophisticated capabilities or flexibilities may frequently become a source of confusion and annoyance for many developers. Hope this list helped you in understanding how some of these typical mistakes affect what you can do with C++. Keep these points in mind to avoid making similar mistakes.

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