6. Length Check

Sometimes you may have data which always has the same number of characters.

For example a UK landline telephone number has 11 characters.

A length check could be set up to ensure that exactly 11 numbers are entered into the field. This type of validation canot check that the 11 numbers are correct but it can ensure that 10 or 12 numbers aren't entered.

A length check can also be set up to allow characters to be entered within a certain range.

For example, postcodes can be in the form of:

CV45 2RE (7 without a space or 8 with a space) or

B9 3TF (5 without a space or 6 with a space).

An input field expecting a post code entry could have a rule that it must be between 5 and 8 characters.