i have some php to show result as JSON like this

$dp = $_GET['dp'];

$query = mysql_query("select trip_id, trip_desc from current_data where dispatcher='".$dp."'");

$json = array();    

while($row = mysql_fetch_assoc($query)){

    $tripdata["code"]=$row["trip_id"]." - ".$row["trip_code"];

    $json[] = $tripdata;

}

echo json_encode($json);

and result like this

[{"code":"S1.001 - UK"},{"code":"S1.002 - US"},{"code":"S1.003 - CA"}]

How to add value in First Result of my JSON, i want to result like this?

 [**{"code":"Select Country"}**,{"code":"S1.001 - UK"},{"code":"S1.002 - US"},{"code":"S1.003 - CA"}]

Thanks

Push the first value to the array before the while loop:

$json[] = [
       'code' => 'Select Country',
     ];

while($row = mysql_fetch_assoc($query)){

    $tripdata["code"]=$row["trip_id"]." - ".$row["trip_code"];

    $json[] = $tripdata;

}

echo json_encode($json);

This will add a the desired value in the beginning of json.

Note:

mysql_* is deprecated as of php-5.5 and removed as of php-7. So instead use mysqli_* or PDO.
Why shouldn't I use mysql_* functions in PHP?