Java script validating form
At last we check the length of the string and permit only phone numbers with 10 digits. When the user clicks the Submit button on the form, the form data is sent to a Java Script validation function that checks each field to make sure that it is in the appropriate format.
Java Script is one of the most popular languages in Full-Stack, Front-end, and Back-end Development.
At first we use regular expression and the replace() method to clear out any spacer characters.
Next, we use the is Na N() function to check if the phone number contain only numbers.
Next, we use regular expression and the test() method to check the field for a compliance.
Also we will use trim() function that will trim leading whitespace off the string.
validate Email ( ) Next we want to see if the email address the user entered is real.
For example, if you are going to send an email confirmation letter, the email address should be included in the form fields, and it should be an email address that works.This can make filling out the form tedious, and people might stop in the middle.If you use the following script and Perl source you will know how to validate an entire form at once, displaying a series of error messages that your reader can then go back and fix.If its not blank, we check the length of the string and permit only usernames that are between 5 and 15 characters.Next, we use the Java Script regular expression /\W/ to forbid illegal characters from appearing in usernames.