The entire code for email validation will with React Hook library look like this: But let me give you a hint. A nice rule of thumb to follow is: Validate all the external sources of your application. You don't need to be an expert in email validation, IP geolocation, etc. Vue makes building Javascript applications extremely quick and simple. In modern browsers, the Easy approach is to do email pattern validation with inbuilt html5 language. [a-z]{2,4}$', "^[a-z0-9._%+-]+@[a-z0-9.-]+\. Note that this doesn't catch some valid email addresses, like these emoji ones: @Toastrackenigma if someone is using an emoji email doesn't deserve to subscribe to my website. First, you need to install Formik: npm i formik. An example of data being processed may be a unique identifier stored in a cookie. !#$%&'*+/=?^_`{|}~-][emailprotected][a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)*$/. I think the function is too complex to be ported and used in JavaScript. How to provide types to JavaScript ES6 classes. This allows the entry of so many invalid email addresses it is useless advice. How could I achieve this? You could possibly check if the domain exists with a dns lookup. Its pretty straightforward. (str.length - lastDotPos) > 2: There should be enough characters after the last dot to form a two-character domain. In general, it is recommended to use libraries for complex forms containing email validation. Once you enter a valid email, the error message will disappear. see. Add the type attribute to the input form, then head back to localhost and try inputting something other than an email string into the input. For UI validation, I'm good with the most basic check of looking for an @ sign. To verify an email address properly, you will need to send an activation link/code to that email. Not only do they manage to succinctly cover the hot news in the JavaScript world for the week but it they manage to add a refreshing humor to it all. Here, inside the