As you can see, it's not that hard to build a validation system on your own. If the field's value is lower than the min attribute or higher than the max attribute, the field will be invalid.
Form data validation Learn web development MDN
For legacy browsers, it's possible to use a polyfill such as Hyperform to compensate for the lack of support for the constraint validation API. This allows to easily make valid fields adopt an appearance that helps the user confirm that their data is formatted properly. This API consists of a set of methods and properties available on specific form element interfaces:.
There are many libraries available to perform form validation; you shouldn't hesitate to use them. This validation descriptor is only for check boxes.
More and more browsers now support the constraint validation API, and it's becoming reliable. To understand what form validation is, why it's important, and to apply various techniques to implement it.
Provide the value of the check box instead of??
In this example, the element is used to create interactive controls for web-based forms in order to accept data from the user; a wide variety of types of input data and control widgets are available, depending on the device and user agent.
Limits the length of the input. We want to make filling out web forms as easy as possible. If the information is correct, the application allows the data to be submitted to the server and usually saved in a database; if the information isn't correct, it gives you an error message explaining what needs to be corrected.
If the entered data follows all of the specified rules, it is considered valid; if not, it is considered invalid.