How do I prevent multiple-definition linker errors?

In C++, multiple-definition linker errors occur when the same function or variable is defined in multiple translation units. This typically happens when header files are improperly managed. To prevent these errors, you can use include guards or `#pragma once` to ensure that a header file is only included once in a single translation unit.

Here’s an example of how to use include guards:

// myheader.h #ifndef MYHEADER_H // Check if MYHEADER_H is not defined #define MYHEADER_H // Define MYHEADER_H void myFunction(); // Function declaration #endif // End of guard

By wrapping your header file content with these preprocessor directives, you can prevent multiple definitions when the header is included in different source files.


Keywords: C++ multiple-definition errors linker errors include guards #pragma once header files.

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