[Not getting return values in $getJSON object]

Javascript:

$getJSON("path", function(data){alert(data.name)})

Guys in this line "data" is not working as an object. name is unrecognizable here. 
I am sending multiple outputs in php using json_encode() function but not able to get those values in javascript file.
 

PHP Code:

$book = array("name"=>"Hussam", "num"=>1);

echo json_encode($book);