In the last (for now) JavaScript tutorial on form field validation we consider the need to validate fields together. Once you have individually validated each of the fields on your form and know that they all contain values that are valid for the field you then need to consider if that value is also valid when the other fields on the form contain the values that they contain.

Cross Field Validation

Just how hard you will find leaning JavaScript to be will depend on what you already know. Most people who are considering learning JavaScript will already know HTML and may know another programming language (or may be considering learning another language at some point). So here we'll look at just how difficult learning JavaScript is as compared to learning HTML and as compared to learning another language (whether you already know one or not).

How Hard is JavaScript To Learn?

It isn't often that there is anything newsworthy relating to JavaScript and this is probably the most significant JavaScript related event in years. Those responsible for the standards upon which JavaScript is based after many years of discussion on ECMAScript 3.1 versus ECMAScript 4 have finally reached agreement and actually approved a new ECMAScript standard. This standard isn't either of those that have been under discussion for so long and instead goes by the name ECMAScript 5. Read the approved ECMAScript 5 Standards to find out what the browsers will need to add to future versions in support of JavaScript.

The seventh Regular Expression tutorial shows you how to group characters together into classes. Any character within a class can provide a match between the regular expression and text being tested.

Character Classes