Validating text in javascript

30 Apr

It makes your page much more user-friendly, and takes out the frustration of having to fill out the same form repeatedly.It's also very precise, as you can point out the exact field where there's a problem.We will create Java Script functions (one for each input field whose value is to validate) which check whether a value submitted by user passes the validation.All those functions are called from another function.We're going to be checking the form using a function, which will be activated by the form's Validating this form would be considerably simpler than one containing radio buttons or select boxes, but any form element can be accessed.Below are the ways to get the value from all types of form elements.The name can’t be empty and password can’t be less than 6 characters long. The user will not be forwarded to the next page until given values are correct.In this document, we have discussed Java Script Form Validation using a sample registration form.

validating text in javascript-82

General questions about form scripts here should be posted to The Java Script Forum.If you want to catch that specific scenario you could add an additional check. Simply trimming the string before the length check will handle this case.These scripts (and a few tutorials) all deal with Javascript forms.When you submit a form to a CGI program that resides on the server, it is usually programmed to do its own check for errors.If it finds any it sends the page back to the reader who then has to re-enter some data, before submitting again.If that conversion to a number fails, the expression will result in result is then compared to the original value you passed in.Since the left hand side is now numeric, type coercion is again used.A Java Script check is useful because it stops the form from being submitted if there is a problem, saving lots of time for your readers.The CGI script is still more reliable, as it always works regardless of whether Java Script is enabled on the client-side or not; but having this extra safety barrier is a nice thing to have in place.Now that the input from both sides was coerced to the same type from the same original value, you would think they should always be the same (always true).However, there's a special rule that says , and so a value that can't be converted to a number (and only values that cannot be converted to numbers) will result in false.