Validation

Validation

1. Range check

   • Checks the numbers are between a certain range
     • A movie site would check that a date of birth is before a certain date when rating 15 rated movies

2. Format check

   • Shopping cites may resrict poscodes to the following combination of letters
   • Makes sure that the correct mix of letters and numbers are entered

3. Presence check

   • Checks tha a field in not empty
   • When signing up to social networking site, the username field must be filled in

4. Check digit

   • An extra number added to the end of a longer set of numbers
     • Worked out by performing a calculation on the longer set of numbers