std::logic_error in C++

In this article, we will discuss the std::logic_error method in C++ with its syntax, example, and benefits.

What is the std::logic_error method in C++?

The exception class in C++ declared in the header file is called std::logic_error. It is used to report logical errors in a program, including the breaking of logical postconditions or preconditions. This class derives from std::exception, the standard exception class.

Syntax:

Here's the definition of std::logic_error in the C++ Standard Library:

As we can see, std::logic_error provides two constructors:

• explicit logic_error(const string& what_arg): It creates an object of logic_error with a message given as a string in std::string format.
• explicit logic_error(const char* what_arg): It creates an object of logic_error with a message given as a string in C format (const char*).

Use the std::logic_error function to signal that a logical error has happened while a program is being executed. It usually indicates that a condition that compromises the program's logical validity has been encountered, such as accessing an invalid state or providing invalid inputs to a function.

Example:

Let us take an example to illustrate the std::logic_error function in C++.

Output:

Explanation:

• In this instance, the divide function throws a std::logic_error, resulting in a divide-by-zero error, if the second argument, y, is zero. Following that, this exception is caught by the main function, which then prints an error message.
• A useful tool for organizing and recording logical errors in C++ programs is Std::logic_error. It is one of the several standard exception classes available in the C++ Standard Library for different error handling scenarios.

Benefits of std::logic_error

In C++, the exception class std::logic_error is helpful for several reasons.

1. Clarity of Intent: The code is more expressive and clear when std::logic_error is used. This exception quickly indicates a logical problem, such as invalid arguments or states, as soon as we come across it.
2. Separation of Concerns: We can distinguish between handling exceptions other than logic-related ones by throwing std::logic_error. Writing better structured and maintainable code can benefit from this.
3. Standardization: Because std::logic_error is a member of the C++ Standard Library, its behaviour and interface are standardized. This consistency across many applications and libraries makes error handling easier.
4. Hierarchy of Exceptions: Because std::logic_error is a descendant of std::exception, hierarchical exception handling is possible. It implies that we either catch std::logic_error directly or catch more general exceptions like std::exception to handle different error cases.
5. Informative Error Messages: Descriptive error messages can be supplied during the construction of a std::logic_error object, which can help debug and determine the error's root cause.
6. Robustness: We can identify and address logical issues early in the program's execution by utilizing std::logic_error, which may help to avoid unexpected behaviour or crashes.
7. Consistent Error Handling: By using standard exception classes like std::logic_error, we can follow best practices in error handling and make our code more predictable and comprehensible for other developers.

Conclusion:

Overall, std::logic_error offers a standardized and practical method for handling logical errors in C++ programs, improving the code's maintainability and dependability.