====== PHP Notes ======

===== PHP Cheat Sheet =====

Following is basic PHP language info, to refresh my memory.

  * http://php.net
  * {{:programming:php:php_reference_sheet.pdf|}}

==== Syntax ====

   * Like Java, each line needs a semicolon
   * Like Java, Comments
     * <nowiki>//</nowiki>
     * /*  multi line */
     * # Comment text (unlike Java)

==== Relational Operators ====

  * == (Equal
  * === (Equal with type comparison)
  * <nowiki>! (logical NOT), && (logical AND), || (logical OR), xor (logical XOR)</nowiki>

==== Variables ====

   * **Data Types:** integer, float, boolean, string, array, object, resource, NULL
   * $variablename = "hello";
   * $arrayname = array();
   * $arrayname = array("apple", "pear", "plum");
   * $arrayname = array("apple" => "red", "pear" => "yellow", "plum" => "purple");

==== If Else ====

<code php>
   if (condition 1) {
      statement 1; }
   elseif (condition 2) {
      statement 2; }
   else {
      statement 3; }
</code>

==== For Loop ====

**Like Java**
<code php>
   for (<intialize>;<condition>;<update>) {
      statements;
   }
</code>

**Unlike Java - foreach**
<code php>
  foreach ($arrayname as $arrayitem) {
      statements;
      break;
      continue;
   }
   foreach ($arrayname as $key => $value) {
       statements;
   }
</code>

==== Common Functions ====

   * sort($arrayname); (Sort array assigns new keys)
   * asort($arrayname); (Sort array maintain keys)
   * rsort($arrayname); (Sort array in reverse, new keys)
   * arsort($arrayname); (Sort array in reverse, maintain keys)
   * count($array); (Count elements);
   * count($array, COUNT_RECURSIVE); (Count multidimensional array);

==== User-Defined Functions ====

<code php>
   function myFunction ($myparam = "default value") {
   
      return "I'm done.";
   }
</code>

==== Class structure ====

<code php>
   class MyClass {
   
      public $myTitle = "hello";
      public function myFunction($myparameter = "default value") {
      }
   
   }
</code>

**Declare and Use Class**

  * $variable = new class_name();
  * $variable->function_name();
  * class_name::function_name(); (Static call)