Data validation in programming is a crucial process that ensures the correctness, usefulness, and security of data. It involves checking inputted data against specific criteria or standards before it’s processed by the program. This can be done through various methods such as type checks, range checks, format checks, and presence checks.
Type checks ensure the data matches the expected datatype. For example, if an integer is expected, the program will reject non-numeric inputs. Range checks confirm the data falls within a certain range. Format checks verify the data follows a particular pattern like email addresses must include ‘@’ symbol. Presence checks make sure essential fields are not left empty.
Validation helps prevent errors, maintain data integrity, and protect from malicious attacks like SQL injection. However, it doesn’t guarantee accuracy as users can still enter incorrect but valid data. Therefore, it should be used alongside other error-checking techniques for robustness.
