Validierungsfunktion

A Validierungsfunktion, or validation function in English, is a piece of code designed to check if a given input or data meets specific criteria or rules. Its primary purpose is to ensure data integrity and prevent errors by confirming that the data is in the expected format, range, or conforms to business logic.

These functions are crucial in various software development contexts, including form processing on websites, database input, API interactions, and configuration file parsing. For example, a validation function might check if an email address has a valid format, if a numerical input is within an acceptable range, or if a required field has been filled out.

The output of a validation function is typically a boolean value, indicating whether the input is valid or not. In more complex scenarios, it might also return an error message explaining why the validation failed, which can then be presented to the user or logged for debugging. Implementing robust validation functions helps to build more reliable and secure applications by catching invalid data early in the process.