Use Excel data validation to prevent duplicate values in a column Your email has been sent Prevent duplicates before they happen by combining a simple function with data validation. Excel has built-in ...

Granted, that single line RegEx looks like a random garble of characters at first glance. In reality, it is a carefully constructed set of rules to dictate a pattern match on a string. As a primer, ...

You might often want to validate parameters in your methods to ensure they have valid data. Most importantly, you might often want to protect your publicly exposed API methods by ensuring that the ...