For example, you might use data validation to calculate the maximum allowed value in a cell based on a value elsewhere in the workbook.
In the following example, the user has typed abc , which is not an acceptable value in that cell.
Inform users that the data they entered is invalid, without preventing them from entering it. When an Information alert message appears, users can click OK to accept the invalid value or Cancel to reject it.
In this concise course, Excel expert Dennis Taylor provides quick and easy tips to help you avoid making common mistakes. If users ignore the input message and enter a number that is not valid, you can show them an error alert. Check 'Show error alert after invalid data is entered'. You can use Excel's Go To Special feature to quickly select all cells with data validation.You can use data validation to restrict the type of data or the values that users enter into a cell.One of the most common data validation uses is to create a drop-down list.