PHP Tutorial - PHP Form Hidden Field

A hidden field is not displayed on the page.

It simply stores the text value specified in the value attribute.

Hidden fields are great for passing additional information from the form to the server.

<label for="hiddenField">A hidden field</label> 
<input type="hidden" name="hiddenField" id="hiddenField" value="" />

Example

The following form uses hidden field to store number of tries.


<?php//from w  w w .  j av a2s  .c  om
  $num_to_guess = 42;
  $message = "";
  if (! isset ( $_POST ['guess'] )) {
    $message = "Welcome!";
  } else if ($_POST ['guess'] > $num_to_guess) {
    $message = $_POST ['guess'] . " is too big!";
  } else if ($_POST ['guess'] < $num_to_guess) {
    $message = $_POST ['guess'] . " is too small!";
  } else {
    $message = "Well done!";
  }
  $guess = ( int ) $_POST ['guess'];
  $num_tries = ( int ) $_POST ['num_tries'];
  $num_tries ++;
  ?>
<html>
<body>
 <?php print $message?>
 Guess number: <?php print $num_tries?><br />
<form method="post" action="<?php
print $_SERVER ['PHP_SELF']?>">
<input type="hidden" name="num_tries"
  value="<?php
  print $num_tries?>" /> Type your guess here: <input type="text" name="guess" value="<?php
  print $guess?>" />
</form>
</body>
</html>