POST content is empty at reception

I have a string that I would like to pass from JS to PHP via a hidden input, but the POST form does not return anything at arrival (I checked it with a var_dump($_POST)), which never happened to me at all.

Here is my HTML code:

<form action='' id='hash-form'>
    <input type='hidden' id='hash' name='hash'/>
</form>

Here is my JS code for changing the value and submitting:

document.getElementById("hash").value = content;
console.log(document.getElementById("hash").value);
document.getElementById("hash-form").submit();

Thanks in advance!

>Solution :

The form lacks of the method attribute, thus it’s GET by default, not post.

Add method="POST" into a form tag.

What is the default form HTTP method?