I have been able to complete the repeating and exiting sections of this little project but have been unable to prevent errors caused by invalid user inputs, namely those caused by a String being inputted instead of the desired Int or Double.

My goal is to prevent the error and instead ask for a valid input.

The rules may be implemented through the automated facilities of a data dictionary, or by the inclusion of explicit application program validation logic.

I am currently writing a basic Calculator that can add, subtract, multiply and divide two numbers and have that core element working correctly.

My "one step further" in this case was to make the program repeating with the option to exit via user input and to prevent any errors due to invalid user inputs.

Also, the attribute can be added to form controls, to programmatically indicate that they are required.

Most current web browsers support this attribute and will communicate missing required input to the user, using standard web browser dialog mechanisms.

Dev Kit is a MSYS/Min GW-based toolkit than enables you to build many of the native C/C extensions available for Ruby.

Dev Kit was previously included in the Windows installer, but now requires a separate download and installation.In computer science, data validation is the process of ensuring that a program operates on clean, correct and useful data.It uses routines, often called "validation rules" "validation constraints" or "check routines", that check for correctness, meaningfulness, and security of data that are input to the system.From what I have gathered, my problem can be addressed through the use of a Try/Catch Statement but I have no idea how to implement such a statement correctly.My best attempts, following similar-ish examples online have been met with failure, which I think is simply down to the way I have coded the program itself.Unfortunately, will happily convert and assign the "12" and leave the "w4" in the input stream, fouling up the next read.