When writing json contain arabic char it appear "??????????????"
$con = mysqli_connect($host,$username,$password,$db);
$q = mysqli_query($con,'select `product_id`, `product_name`, `sku`, `price`, `final_price`, `minimal_price`, `special_price`, `image`, `small_image`, `thumb_image`, `short_description`, `href`, `is_favorite`, `category_name` from products_uae_ar');
mysqli_query($con, "SET NAMES 'utf8'");
mysqli_query($con, "SET CHARACTER SET 'utf8'");
print_r( json_encode($output));
This may not be the complete solution but you should tell the connection you want to use UTF-8 before issuing a query
$con = mysqli_connect($host,$username,$password,$db);
mysqli_query($con, "SET NAMES 'utf8'");
mysqli_query($con, "SET CHARACTER SET 'utf8'");
mysqli_set_charset($con, 'utf8mb4');
$q = mysqli_query($con,'select `product_id`, `product_name`, `sku`,
`price`, `final_price`, `minimal_price`,
`special_price`, `image`, `small_image`,
`thumb_image`, `short_description`, `href`,
`is_favorite`, `category_name`
from products_uae_ar');
print_r( json_encode($output));
It would also be a good idea to read this post