i want to pass a php aray to jQuery:

$.getimagesarr = function() {
    $.getJSON('operations.php', {'operation':'getimglist'}, function(data){
        var arr = new Array();
        arr = data;
        return arr;
    });  
}

var data = $.getimagesarr();
if (data){
 jQuery.each(data, function(i, val) {
     ....
    });
}

it return undefined

in php i have this:

function getimglist(){
    $results = $_SESSION['files'];
    echo json_encode($results);
}

it is possible?