Here I am giving you the form validation codes in Java Script. These are simple meta characters which do pattern matching. If the entered characters in the field is not in lower case or upper case. When it’s about checking contact field or zip code field, one need to check whether only the number have been entered or not.Regular expression helps you in pattern matching in string. : Matches any single charcter except a new line : Matches the preceding character or repeated character. The basic expression for matching entered value as number in the field is: /^[0-9] $/.At the end, there's a little exercise to keep you busy too!Form validation is the process of checking that a form has been filled in correctly before it is processed.If the string value is numeric, it will return true, otherwise it will return false.Just about any website or web application will require user input in one form or another.A much better way of solving this problem is to include inline validation that checks the user’s input as she progresses.This alerts the user to any errors and allows her to correct her errors before proceeding and losing her progress.
Shows you how to write a script that ensures your form is filled in correctly before it's sent to your server.
Syntactic validation should enforce correct syntax of structured fields (e.g.
SSN, date, currency symbol) while semantic validation should enforce correctness of their values in the specific business context (e.g.
Input validation should happen as early as possible in the data flow, preferably as soon as the data is received from the external party.
Data from all potentially untrusted sources should be subject to input validation, including not only Internet-facing web clients but also backend feeds over extranets, from suppliers, partners, vendors or regulators, each of which may be compromised on their own and start sending malformed data.