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 ...

The first step to handle user input in JavaScript web games is to detect what kind of input device the player is using, such as a keyboard, a mouse, a touch screen, or a gamepad. This will help ...

Sanitizing user input is key for protecting your site. Effectively, a hacker can run code on the user’s browser by entering it in a place where the user can input text or value (such as a date). Of ...

In some rare cases is necessary to filter what users paste in the exact moment they do it, one reason is to allow users to paste URLs with space characters which otherwise would be ignored by any ...