schlitt.info - php, photography and private stuff
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:Author: 		Tobias Schlitt
:Date:			Wed, 19 Nov 2008 23:29:46 +0100
:Revision: 		1
:Copyright:		CC by-nc-sa


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Nice PHP code
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:Description:
    At our weekly usergroup meeting, which is taking place just right now, we
    again discussed our beloved topic, the Ternary Operator. I like that thing
    really much and I believe it makes code much more readable in a lot of
    cases. Anyway, I tend to stack ternary operators and I didn't even know,
    that the PHP manual recommends to not do that. I think this recommendation
    is only valid of you don't add appropriate braces, to indicate the
    precendences. Anyway, while having a beer, we thought about some more
    "funny" things you could do with it... For example, executing mutliple
    statements, within one section of the operator... here is the result:

At our weekly usergroup meeting, which is taking place just right now, we
again discussed our beloved topic, the Ternary Operator. I like that thing
really much and I believe it makes code much more readable in a lot of cases.
Anyway, I tend to stack ternary operators and I didn't even know, that the PHP
manual recommends to not do that. I think this recommendation is only valid of
you don't add appropriate braces, to indicate the precendences. Anyway, while
having a beer, we thought about some more "funny" things you could do with
it... For example, executing mutliple statements, within one section of the
operator... here is the result:

::

    echo ( ( 1 == 1 ) ? call_user_func( create_function( '$a, $b', 'return ($a * 2) + $b;' ), 10, 15 ) : 0 );

**Update**:

Some more funny constructs after some more beer. I simply love lambda
calculus. :)

::

    call_user_func(($func = create_function('$func, $x', 'echo $x; return ($x < 10 ? $func($func, $x+1) : $x);')), $func, 1);


..
   Local Variables:
   mode: rst
   fill-column: 79
   End: 
   vim: et syn=rst tw=79

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Comments
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- Derick at Thu, 01 Feb 2007 20:28:44 +0100

  Don't you ever dare to commit this sort of code though! :D

- Richard Thomas at Thu, 01 Feb 2007 20:46:23 +0100

  Hate them with a passion, yes they are easy to understand if you don't go
  stack crazy but they make scanning through code harder.

- Ivo Jansch at Thu, 01 Feb 2007 21:22:54 +0100

  When used properly, it can give you pretty clean code. Sometimes I encounter
  them in the most complex situations, in which they only cause confusion.

- Thomas Koch at Thu, 01 Feb 2007 21:35:52 +0100

  Somebody on #php.de showed me another nice application. I'm only not sure,
  if it saves you any time. In Python you can give a default value when
  assigning a the value to a variable. That's usefull for example, when a you
  want to give a default if a function returns null or false. In PHP write:
  $var = ($var = functionCall()) ? $var : 'no return from function!';

- Toby at Thu, 01 Feb 2007 21:38:07 +0100

  You should read internals and search for ifsetor operator.

- Ivo Jansch at Thu, 01 Feb 2007 22:25:30 +0100

  It would be cool if this worked:

  $var = $_REQUEST["somevar"] || "default";

  instead of 'ifsetor'. But this is syntactically impossible.

- Armand at Fri, 02 Feb 2007 10:17:20 +0100

  "...I believe it makes code much more readable..."

  Are you joking? It's horrible!

- Toby at Fri, 02 Feb 2007 10:50:14 +0100

  Please read exactly, what I wrote. The code shown here is absolutly
  unreadably, that is true. But there are cases, where the ternary operator
  makes code more reabale that nested ifs, I think.

- Armand at Fri, 02 Feb 2007 11:11:43 +0100

  I cant remember any situation in my programming practice where such a style
  was helpful. I consequently reject such a style in my projects. All what i
  can say is: If you dont use it you havent to break with such a habit, which
  is  painful.

- Ivo Jansch at Fri, 02 Feb 2007 11:18:50 +0100

  I remember that in the past, there were some Code Poetry contests in the
  perl community for writing the most beautifully constructed code. Maybe we
  should do something similar sometime for PHP :)

- Tobias Struckmeier at Fri, 02 Feb 2007 17:01:00 +0100

  Imageine code like this:

  $myvar = $http->hasVariable( 'foobar' ) ? $http->variable( 'foobar' ) :
  'defaultValue';

  This is more readable as for example:

  $myvar = 'defaultValue'; if( $http->hasVariable( 'foobar' ) ) {

      $myvar = $http->variable( 'foobar' ); }

  Because in one line you see there is an assignment only when a value exists.
  Otherwise you have to read the whole if statement. But that is only one
  example.

- Armand at Fri, 02 Feb 2007 18:29:22 +0100

  what about encapsulation? some thing like this:

  class test{ ... ... function hasVariable( $var_name ){ if(
  $this->http->hasVariable( $var_name ) ){ return $this->http->variable(
  $var_name ); }

          else{ return 'defaultValue'; }

      } }

  I think it's more maintainable and readable. (ok it depends on what you
  understand under readable)

- Armand at Fri, 02 Feb 2007 19:14:09 +0100

  from my assembler time. Most of the related web pages still exists with
  beautiful masterpieces. ..., 65-byte Life Simulator,...

  http://www.df.lth.se/~john_e/gems.html --- code poetry .

- Jan at Mon, 19 Feb 2007 18:02:27 +0100

  What makes your if-statements unreadable are the insane bracketing rules you
  seem to force upon yourself.

  Try bracketing and indenting pragmatically instead of dogmatically.

  Compare

  <pre> if ($cond) {

      $a = 1; }

  else {

      $a = 2; }; </pre>

  to

  <pre> if ($cond) $a = 1; else       $a = 2; </pre>

  Unfortunately my point is kinda hard to recognize here because your comments
  don't support the pre- HTML Tag