html checkboxes to php

I have the following code for checkboxes in html:

    <label>Choose type of order :</label>

   <input type="checkbox" name="check_list[]" value="to1" > Energy Bar<br>
   <input type="checkbox" name="check_list[]" value="to2"> Tents <br>
   <input type="checkbox" name="check_list[]" value="to3"> Canned foods <br>

   </p>

And the php code is :

<?php
$t01=$_POST['check_list'][];

require("fpdf.php");
$pdf = new FPDF();
$pdf->AddPage();
foreach($_POST['check_list'] as $check) {
            echo $check; 

$pdf->Cell(50,10,"Total order :",1,0);
$pdf->Cell(50,10,"$t01",1,1);



    }
  }  
$pdf->Output();

}

?>

However when I run this on my server it shows me the following error:

Fatal error: Cannot use [] for reading in /Applications/XAMPP/xamppfiles/htdocs/demo/form.php on line 11

How can I correct this problem