Validation

Validation and verification

What is validation?

• Ensures data being entered is both sensible and possible

• Good validation can prevent program from breaking (or even hacking)

Open Ended

If you want need to ask user to input his age, what do you want to make sure in your program?

Common types of validation

• Range Check (data must be numerical data in a range)

• Presence Check (Data must be entered)

• Type Check (Data must be a certain acceptable data type)

• Lookup check (Data must be within a list of options)

• Length Check (Usually for string, the length of the string must be within a given range)

• Format Check (The data has to conform to a specific format)

Multiple Choice

What is this type of validation?

• Range

• Presence

• Lookup

• Format

Multiple Choice

Which validation check if the value is a number or not?

• Presence

• Type

• Lookup

• Format

Multiple Choice

Which validation can check if you enter an email address correctly?

• Presence

• Type

• Lookup

• Format

Multiple Choice

Which validation can check if you enter gender?

• Presence

• Type

• Lookup

• Format

More about validation

• Usually validation is done automatically by computer

• Most of the time, more than one type of validation check might be needed for a set of data

Multiple Select

Check all the validation needed for entering a student class and class number

• Range

• Prescence

• Type

• Lookup

• Length

Check Digit

Fill in the Blank

How many digits are there in the ISBN in your textbook?

Check digit

• To verify if a series of number is entered / transferred correctly

• Usually check digit is the last digit

• A special algorithm is used to calculated the check digit