How to print_r $_POST array?

I have following table.

<form method="post" action="test.php">
  <input name="id[]" type="text" value="ID1" />
  <input name="value[]" type="text" value="Value1" />
  <hr />

  <input name="id[]" type="text" value="ID2" />
  <input name="value[]" type="text" value="Value2" />
  <hr />

  <input name="id[]" type="text" value="ID3" />
  <input name="value[]" type="text" value="Value3" />
  <hr />

  <input name="id[]" type="text" value="ID4" />
  <input name="value[]" type="text" value="Value4" />
  <hr />

  <input type="submit" />
</form>

And test.php file

<?php 

  $myarray = array( $_POST);
  foreach ($myarray as $key => $value)
  {
    echo "<p>".$key."</p>";
    echo "<p>".$value."</p>";
    echo "<hr />";
  }

?>

But it is only returning this: <p>0</p><p>Array</p><hr />

What I'm doing wrong?