Why does jQuery ajax (JSONP) work without `&callback=` but fails with `&callback=functionname`

Question

I need to do a JSONP call.

Ajax function call :

$.ajax({
    url: myPath,
    dataType: 'jsonp',
    success: function(data) {
        alert("hello"); 
    }
});

getJSON function call :

$.getJSON(myPath + '&callback=prova?', function(data) {
    alert("hello");
});

with getJSON (using &callback=prova for setting JSONP protocol) I get an error 200. .ajax() works as well. Why? I want to use getJSON here...

Answer 1

You should use callback=? and not callback=prova? if you want your request to be treated as JSONP:

$.getJSON(myPath + '&callback=?', function(data) {
    alert("hello");
});
​

Answer 2

Try this

$.getJSON(myPath + '?callback=prova', function(data) {
    alert("hello");
});