2020 Study Design - Validation and Input Masks

[Chessnutter]

I did Software Development in 2019 and I think I scored very well (validation is in the Software Development SD).

My textbook for next year says there are 4 types of validation; Existence, Type, Range and Input Mask. I have not heard of an input mask in software development, it was not mentioned in the textbook or in any of the past VCAA exams. I did find a mention of an input mask in the 2016 exam notes.

The definition the textbook gave for an input mask check was checking to see if the number of characters entered was the accepted number.
Isn't this just a range check? For example, checking that a postcode has 4 digits is just checking if it is a number between 0 and 9999, or possibly in the set of strings composed of 4 digits ({"0000", "0001", "0002" ... "9999"}). 

[Aaron]

fyi in Access (it's the only example I can think of off the top of my head that uses input masks lol) an input mask is a specific string guiding the user to input something specific into the field.

For example, say you have a student code that is an alphanumeric string of 7 characters and must be in the format abc1234 (3 letters followed by 4 digits), an input mask would be something like LLL0000 which states we must have 3 letters THEN 4 digits in this order. The digits can be 0 - 9 and the letters can be a-z or A-Z or a combination of both.

Why is it validation? Because it prevents the user from inputting something that violates an intended format. If we wanted (using the same example above) a student code to be 3 letters then 4 digits, the input mask prevents something completely different from being entered in (e.g. other way around).

I don't like this definition one bit:

The definition the textbook gave for an input mask check was checking to see if the number of characters entered was the accepted number.

I'd definitely go and have a look at Microsoft Access Input Mask guides / tutorials etc. that are around. That way, you can get a general understanding of what an input mask is, and try to apply it to whatever software/context you are looking at.

[Chessnutter]

fyi in Access (it's the only example I can think of off the top of my head that uses input masks lol) an input mask is a specific string guiding the user to input something specific into the field.

For example, say you have a student code that is an alphanumeric string of 7 characters and must be in the format abc1234 (3 letters followed by 4 digits), an input mask would be something like LLL0000 which states we must have 3 letters THEN 4 digits in this order. The digits can be 0 - 9 and the letters can be a-z or A-Z or a combination of both.

Why is it validation? Because it prevents the user from inputting something that violates an intended format. If we wanted (using the same example above) a student code to be 3 letters then 4 digits, the input mask prevents something completely different from being entered in (e.g. other way around).

I don't like this definition one bit:
I'd definitely go and have a look at Microsoft Access Input Mask guides / tutorials etc. that are around.

I agree that it is definitely validation, what I was trying to convey was that I understand it as a form of range validation, and if that is the case it's redundant. Your example is a range check (from my Software Dev understanding), you are checking that the input is in the set of alphanumeric strings composed of 3 letters then 4 digits ({"aaa0000", "aaa0001" ... "aab0000" , "aab0001" ... "ZZZ9999"}).

So is an input mask just a more 'specialised' range check?

I checked out what Microsoft claims an input mask to be, and it does not distinguish it from a range check. I believe I understand it based off both your definition and Microsoft's definition though.

Thanks for your help!

[www]

I don't like this definition one bit

Absolutely agree. That definition is awful!

I agree that it is definitely validation, what I was trying to convey was that I understand it as a form of range validation, and if that is the case it's redundant. Your example is a range check (from my Software Dev understanding), you are checking that the input is in the set of alphanumeric strings composed of 3 letters then 4 digits ({"aaa0000", "aaa0001" ... "aab0000" , "aab0001" ... "ZZZ9999"}).

So is an input mask just a more 'specialised' range check?

It might be easier to think of it from an implementation standpoint?

It is significantly easier to apply an input mask to ensure someone is inputting 3 letters then 4 digits (LLL0000) than it is to implement a check that will account for everything from aaa0000 to ZZZ9999.

The input mask will directly prevent someone from entering something that isn't formatted to what is required. A quantity input could have a range check to ensure that it is at least 1 and at most 999, but say there's a requirement of the database that all quantity entries must be written with 3 digits (000). An input mask would prevent someone from entering in 1 because it forces them to enter in 001.

Input masks can do other things (e.g. making sections of an input lowercase or uppercase, specific spacing on the input such as in a phone number) and knowing some of them may make it easier to distinguish these validation techniques.

[Noot313]

  Don't know if the same definition was taught in software development, but from what I can recall from informatics:
 
An Input Mask is a type of validation that ensures the reasonableness of the data entered by forcing a particular format the data must take. In essence it mixes an existence check, a range check and a data type check to make sure data fits a particular form.

Example: Phone Number might need to be in the form "(03)925 664 63" when inputted into Microsoft Access. Applying an input mask will save you the trouble of using multiple different validation techniques.

The answer I've given could differ to the more technical perspective adopted by the SD route, so take it with a grain of salt.