An introductory article on undefined behavior in C and C++, an important topic for people who write or analyze code in these languages.
The article introduces a guide to undefined behavior in C and C++, a relevant subject for anyone writing or analyzing programs in these languages.
When studying the topic, start by identifying operations in the code whose results may not be defined by the language rules. Do not assume the same code will always have the same effect across different compilations.
Use small examples to investigate each case, and compare observed behavior with the applicable documentation and rules. A result that seems consistent in one test does not prove that the program is correct.
If you use an AI tool to study or apply the material, do not include confidential code, credentials, or personal data without authorization. Share only the necessary excerpt, and review the response before using it.