About execution order of onclick in JavaScript

May 29, 2023

I have a question about the execution order of the onclick attribute in JavaScript.

I would like to know why the function written after form submission is executed.
Why is it not run from above?

<form action="post" name="formTest">
    <button type="button" onclick="A(B)" id="test">test</button>
</form>
<script>
    function A(B) {
        formTest.submit();
        B();
    }

    function B() {
            window.alert('Function B');
    }
</script>

>Solution :

Form submissions, and formTest.submit(), are asynchronous, meaning they are executed but the browser doesn’t wait for them to finish before moving on to the next line of code.

Because submitting a form is a relatively long process compared to firing an alert (ie: you have to make a HTTP request and receive a response from the server) the browser runs formTest.submit(), runs alert(), then the submission completes from the background.