JavaScript: Form Validation & Async Programming

Form validation is a common use case for Javascript. Learners will explore basic steps involved in this process including an overview of asynchronous programming and the use of promises to handle such code in this 10-video course. Key concepts covered here include how to define simple registration forms with text numerical input fields radio buttons check boxes and drop-down menu; how to access individual form elements and their data contents from Javascript; and learning when variables are destroyed by Javascript when a form submission navigates users to a different web page. Begin by observing a variety of form validations for different input fields; learning operations which run asynchronously in your Javascript application; and learning how to use promises to chain the execution of two functions where one depends on the results returned by the other. Next learn a function making multiple asynchronous function calls by using async/await syntax. Finally observe how to use the fetch function to asynchronously retrieve an image file and relate it to the XMLHttpRequest of AJAX.