如何在页面中回显变量数组？

Question

I am just starting learning codes and am writing some codes to echo an array and it give me this error "Warning: Invalid argument supplied for foreach() in C:\xampp\htdocs\ogmtest_server_api.php on line 62" HOW CAN I SOLVE THIS? This is my code:

   if($Result1){
    // script to get business no, amount & merchant id,output to merchant page
      $query="SELECT * FROM customer_order WHERE insert_time=(SELECT max(order_time)from customer_order)";
      $result=mysql_query($query);
      while($row=mysql_fetch_assoc($result)){
          $amount=$row['amount'];
          $id=$row['merchant_id'];
          $payment_mode=$row['mobile_service'];
          switch($payment_mode){               
           case 'TIGO-PESA':
            $result1=mysql_query("SELECT * FROM mobile_client WHERE mobile_service='TIGO-PESA'");
            while($row1=mysql_fetch_assoc($result1)){ 
                 $data=array(
                   'Business no'=>$row1['business_no'],
                   'Payment Mode'=>$payment_mode,
                   'Total Amount Tsh'=>$amount,
                   'Merchant ID'=>$id
                   );
                   }break;

            case 'M-PESA':
            $result1=mysql_query("SELECT * FROM mobile_client WHERE mobile_service='M-PESA'");
            while($row1=mysql_fetch_assoc($result1)){ 
                 $data=array(
                   'Business no'=>$row1['business_no'],
                   'Payment Mode'=>$payment_mode,
                   'Total Amount Tsh'=>$amount,
                   'Merchant ID'=>$id
                   );
                   }break;
            case 'AIRTEL-MONEY':
            $result1=mysql_query("SELECT * FROM mobile_client WHERE mobile_service='AIRTEL-MONEY'");
            while($row1=mysql_fetch_assoc($result1)){ 
                 $data=array(
                   'Business no'=>$row1['business_no'],
                   'Payment Mode'=>$payment_mode,
                   'Total Amount Tsh'=>$amount,
                   'Merchant ID'=>$id
                    );
                   }break;

           default:
           $data=array('error'=>"no payment mode selected");        
        }
     }
           foreach( $data as $value ){
              echo $value;
                 }      
             }
            else{
      echo "wrong";
    }
}

Answer 1

you can use print_r() to print the array. like this:

echo '<pre>';
print_r($data);
echo '</pre>';

if $data is an array. So you can debug it by yourself.

Note that first declare $data as array at the top of script. like: $data = array();