Please provide a script that has some possibility to work, logically too. A proper reproducing script starts with <?php and ends with ?>, is no longer than 20 lines and is self-contained in every way.

Old excampe incorrected!
This excemple correct:

$strCode = 0;
switch( $strCode )		
{
	case 'jpg':
	case 'jpeg':
		echo 'point 0';
		break;
	case 'gif':
		echo 'point 1';
		break;
	default:
		echo 'point 3';
}

<?php
$strCode = 0;
switch( $strCode )		
{
	case 'jpg':
	case 'jpeg':
		echo 'point 0';
		break;
	case 'gif':
		echo 'point 1';
		break;
	default:
		echo 'point 3';
}
?>

Sorry, but your problem does not imply a bug in PHP itself.  For a
list of more appropriate places to ask for help using PHP, please
visit http://www.php.net/support.php as this bug system is not the
appropriate forum for asking support questions.  Due to the volume
of reports we can not explain in detail here why your report is not
a bug.  The support channels will be able to provide an explanation
for you.

Thank you for your interest in PHP.

See http://www.php.net/operators.comparison

0 == 'string'

The right hand side is cast to an integer, in this case the right hand side ends up as 0.