Can I encode an array of 'array objects' in php when using json/ajax?

Hello I was wondering if this is possible?

$results = $stmt->fetchAll();
    $recent_posts = array();
    foreach ($results as $row){
        $post = array(
            'username' => $row['username'],
            'steam' => $row['steam'],
            'skill' => $row['skill'],
            'description' => $row['description'],
            'date' => $row['date'],
        );
        array_push($recent_posts, $post);
    }
    return json_encode($recent_posts);

If this is possible how exactly do I access it in jquery? $

('#order_by').on('change', function(){ 
        $.ajax({ 
            type: "POST", 
            url: "sort_skill_be.php", 
            data: { skill: this.value }, 
            error: function (qXHR, textStatus, errorThrown) { 
                console.log(errorThrown); 
                //alert(errorThrown);
            }, 
            success: function (result) { 
                alert(result[0].skill);  // CAN I ACCESS IT LIKE THIS?
            } 
        }); 
    }); 

This is what I have so far, but I keep getting weird errors. When I added datatype:json I keep getting problems. So I feel I am handling this incorrectly, Thank you for the help!