Learn how to use JavaScript to validate user input in payment systems. Find out how to check the format, length, and value of input, handle invalid input, test and debug validation code, and ...

Hello readers, in this blog we will discuss how to check a valid phone number in the form. sometimes you need to add the validation for the phone number which requires a certain format.we have to ...

A web app that checks user input and determines if it is a valid US phone number using JavaScript, CSS, and HTML. This is part of the freeCodeCamp.org certification JavaScript Algorithms and Data ...