AJAX调用PHP文件：返回值为空

I have a simple ajax call:

function init() {
    $.ajax({
        url: "./myFolder/user.php",
        data: {
            action: "init"
        },
        type: "post",
        success: function (output) {
            console.log("Success");
            console.log("Output: " + output);
        }
    });
}

The PHP init method gets called and simply should return some json data:

function init() {
    $arr = array(
        array(
            "region" => "valore",
            "price" => "valore2"
        ),
        array(
            "region" => "valore",
            "price" => "valore2"
        ),
        array(
            "region" => "valore",
            "price" => "valore2"
        )
    );

    return json_encode($arr);
}

but my console says:

Success
Output:

So the output variable is empty. Where is my json data?

On user.php page you need to do :-

function init() {
        $arr = array(
            array(
                "region" => "valore",
                "price" => "valore2"
            ),
            array(
                "region" => "valore",
                "price" => "valore2"
            ),
            array(
                "region" => "valore",
                "price" => "valore2"
            )
        );

        echo  json_encode($arr);
    }

u should have in your user.php somthing like this:

die(init());