How to pass the value of php to javascript using ajax

Question

i have an array , which has to be passed from backend to frontend using ajax, i am new to ajax i know the syntax but got stuck , below is my code

backend(PHP)

$s_q = "SELECT `ans` FROM `bec_log_response` WHERE session_id=1 AND paper_id=2";
                            $s_res = mysql_query($s_q, $db2);
                            while($row=  mysql_fetch_array($s_res))
                            {
                            echo $row['ans'];  
                            } 

$result = array('ans' => $row['ans'] );

Javascript code

function get_solution()
    {

        $.ajax({
            url: 'waiting.php',
            dataType: 'json',
            type: 'GET',
            timeout: 30 * 1000,
            data: {sol:row},
            success: function(json){   
                $('#saved').html(json.ans);

            },
            error: function(){}

        });

    }

i am getting an error in this code data: {sol:row}.

Answer 1

The response data from php is not in json format..

$result = array('ans' => $row['ans'] );
echo json_encode($result);

add this in your php code

Answer 2

Create a JSON on the PHP Side and catch it with $.getJSON jquery

Server Side:

$row_1 = array();
$s_q = "SELECT `ans` FROM `bec_log_response` WHERE session_id=1 AND paper_id=2";
$result = mysql_query($s_q) or die (mysql_error());

while($r = mysql_fetch_assoc($result)) {
    $row_1[] = $r;
}

$post_data = json_encode(array('ans' => $row_1));

echo $post_data;

Client Side:

  $.getJSON("result.php", function(json) {
            console.log(json)
     $.each( json, function( key, data ) {
           //loop through the json if necessary
     });
  });