Last updated: Sat, 24 Mar 2007

Alternativní syntaxe řídicích struktur

PHP nabízí alternativní syntaxi pro některé z řídicích struktur, jmenovitě if, while, for, foreach, a switch. V každém z těchto případů je základním formátem alternativní syntaxe záměna otvírací závorky za dvojtečku (:) a uzavírací závorky za endif;, endwhile;, endfor;, endforeach;, resp. endswitch;.


<?php if ($a == 5): ?>

A se rovná 5

<?php endif; ?>

Ve výše uvedeném příkladu je HTML blok vnořen do příkazu if napsaném alternativní syntaxí. Tento HTML blok by se zobrazil pouze v případě, že je $a rovno 5.

Alternativní syntaxi lze použít i pro else a elseif. Následující příklad ukazuje strukturu if, elseif a else v alternativním formátu:


if ($a == 5):

    print "a se rovná 5";

    print "...";

elseif ($a == 6):

    print "a se rovná 6";

    print "!!!";

else:

    print "a není ani 5, ani 6";

endif;

Další příklady - viz také while, for, a if.

while

elseif

Last updated: Sat, 24 Mar 2007

add a note User Contributed Notes
Alternativní syntaxe řídicích struktur

jeremia at gmx dot at
28-Jan-2008 06:52


If you wan't to use the alternative syntax for switch statements this won't work:



<div>

<?php switch($variable): ?>

<?php case 1: ?>

<div>

Newspage

</div>

<?php break;?>

<?php case 2: ?>

</div>

Forum

<div>

<?php break;?>

<?php endswitch;?>

</div>



Instead you have to workaround like this:



<div>

<?php switch($variable): 

case 1: ?>

<div>

Newspage

</div>

<?php break;?>

<?php case 2: ?>

</div>

Forum

<div>

<?php break;?>

<?php endswitch;?>

</div>

php dot net at eoasys dot com
24-Oct-2007 03:03


In response to spa:



Yeah, that's for sure! Seems so obvious, but remains a tough sell... I avoid the "Bracket Racket", and use it only where the (ahem) "Clearer Syntax" wasn't implemented.



A further improvement would be a "Noun-Verb" form of end structures. Such as:



if (...):

  while (...):

    ...

    if (...):

      ...

      ...

    ifend;

    ...

  whileend;

ifend;



This would make it yet another level of easier to tell which block end you're looking at. ;-)

spa
16-Oct-2007 04:40


[EDITOR'S NOTE: reference to deleted note removed]





The end_; structure sometimes makes it easier to tell which block statement end you are looking at.  It's much harder to tell which nested block a } belongs to than an end_;

skippy at zuavra dot net
27-Jun-2005 04:32


If it needs saying, this alternative syntax is excellent for improving legibility (for both PHP and HTML!) in situations where you have a mix of them.



Interface templates are very often in need of this, especially since the PHP code in them is usually written by one person (who is more of a programmer) and the HTML gets modified by another person (who is more of a web designer). Clear separation in such cases is extremely useful.



See the default templates that come with WordPress 1.5+ (www.wordpress.org) for practical and smart examples of this alternative syntax.

i a m 4 w e b w o r k at hotmail dot com
12-Oct-2003 04:38


Good tutorial on using alternative control structure syntax at:

http://www.onlamp.com/pub/a/php/2001/05/03/php_foundations.html?page=1

add a note

while

elseif

Last updated: Sat, 24 Mar 2007