Validating event radio group
For example, if the input should be greater than or equal to 10 then the validation is See the demo @Code Pen Common text input patterns like email, URL, decimal number etc are available “ready to use” in the library. also contains a ‘pattern’ validation where you can give a regular expression as a parameter.
Here are some common text pattern validations: See the demo @Code Pen Doing a ‘required’ validation for a Dropdown list is a bit tricky.
If the default option (‘Select …’) has a non-empty value, the required validation won’t give the desired result.
See the demo @Code Pen You can apply the ‘required’ validation to the radio group.
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.
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If you skip the message for a validation, the default message is displayed.
See a complete demo @Codepen The messages parameter is optional.
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.