为什么jQuery ajax响应总是被填充

Question

I noticed that the response of an ajax call with jQuery is never empty. I have the following:

$.ajax({
        type: "get",
        data: { data },
        url: "phpFile",
        datatype: 'text'
 }).done(function( response ) {             

        if (response.length > 2)
        alert(response);
    });

in the php file I only return text if there is an error with a query

echo mysqli_error($conn);

however even when I don't return anything the length is always 2 or greater, does someone knows why or how could I retrieve an empty text?

Answer 1

I'm answering my question just to serve as reference for anyone seeing this.

What I was trying to do was actually a bad practice and the best thing to do as Dipanwita Kundu mentioned is to return a proper success response, false or true with error message.