The HTML onsubmit attribute is an event handler used to specify a script that will run when a <form> is submitted.
Definition and Usage
➔ This event is useful when client-side form validation, displaying confirmation messages, or preventing invalid form submission behavior is required.
➔ If the verification is successful, the data is sent to the server, if the verification fails, the submission is stopped. <form onsubmit="return validateData()"> here the validateData() function returns true or false.
➔ This event works with <input type="submit"> or <button type="submit">
➔ The action attribute specifies the URL where the form data will be sent (usually a server-side script) and the onsubmit script runs before the form is submitted to the action URL.
Syntax
//In HTML
<form onsubmit="myFunction()" id="sample">
<!-- form input elements goes here -->
</form>
//In javascript
document.getElementById("sample").onsubmit=function() {myFunction();};
//OR
document.getElementById("sample").addEventListener("submit", myFunction);
//OR
document.getElementById("sample").addEventListener("submit", (event) => {
myFunction();
});