PHP4 Practical Application (9)

"= =" operator
------------------------

As we have mentioned above, PHP4 adds a new = = operator to test whether the variable has the same type. Here's an example:


--------------------------------------------------------------------------------
<?

if (! $submit)
{
If $submit does not exist, this implies that the form has not yet been submitted
So the first page is displayed

?>

< html>
< head>
< style type= "Text/css" >
td {Font-family:arial;}
</style>

< body>

< form method= "get" action= "cookie.php" >
< table cellspacing= "5" cellpadding= "5" border= "0>

< tr>
< TD align= "Center" >
Please enter any values or data
</td>
< TD align= "right" >
< input type= "text" name= "Yin" >
</td>
</tr>

< tr>
< TD align= "Center" >
Please enter some more values or data
</td>
< TD align= "right" >
< input type= "text" name= "Yang" >
</td>
</tr>

< tr>
< tr>
< TD colspan= "2" align= "Center" >
< input type= "submit" name= "Submit" value= "test!" >
</td>
</tr>

</table>
</form>
</body>



<?
}
Else
{

If $submit does exist, the form has been submitted
So use the following code to process


if ($yin = = = $yang)
{
$result = "Two variable values and types are identical";
}
Else
{
$result = "Two variable values and types are completely different";
}

?>

< html>
< head>
< Basefont face= "Arial" >

< body>
< b><? echo $result;?></b>

</body>

<?
}
?>
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Choose syntax
------------------

PHP also supports a choice syntax for the various control structures currently discussed. For example, you can do this:

--------------------------------------------------------------------------------
<?

if ($elvis = = 0)
{
echo "Elvis has left the building!";
}
Else
{
echo "Elvis is still here!";
}

?>

Or you can do this:

<?

if ($elvis = = 0):
echo "Elvis has left the building!";
Else
echo "Elvis is still here!";
endif

?>
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The second option is exactly the same as the first, in which a simple colon [:] replaces the first large bracket, removes the second large bracket, and ends with a "endif" statement.

These are the contents of the second part. Next time, we'll bring you loops, arrays and more forms-so be sure not to miss it!