Checking Your Work: Validating Input – The Cool Stuff

“You will find this type of comparison especially helpful when
it comes to verifying numbers and validating character strings that
should not have any numbers, such as names, for example. Below are
scripts that apply to our form example in our first article where
we check to make sure the name input is all characters and our
number of years is a whole number. I have also included another
common script that is outside the scope of our example which you
will find useful for checking input to make sure it is formatted
properly.

“The first thing we will need to do is to create some common
variables to hold our expressions that we will use to validate
against. Don’t worry if the expressions don’t make any
sense to you. Creating regular expressions is an art form all its
own. Whenever possible you should try to find an expression that
someone else has already created and tested. Writing one from
scratch can be both time consuming and tedious, especially for the
novice.”

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