1 files changed, 30 insertions, 13 deletions
diff --git a/php.html.markdown b/php.html.markdown
index f0c5c918..ce228870 100644
--- a/php.html.markdown
+++ b/php.html.markdown
@@ -1,14 +1,15 @@
 ---
 language: php
-author: Malcolm Fell
-author_url: http://emarref.net/
+contributors:
+    - ["Malcolm Fell", "http://emarref.net/"]
+    - ["Trismegiste", "https://github.com/Trismegiste"]
 filename: learnphp.php
 ---
 
 This document describes PHP 5+.
 
 ```php
-<?php // PHP code must be enclosed with <?php ? > tags
+<?php // PHP code must be enclosed with <?php tags
 
 // If your php file only contains PHP code, it is best practise
 // to omit the php closing tag.
@@ -30,7 +31,8 @@ echo "World\n"; // Prints "World" with a line break
 // (all statements must end with a semicolon)
 
 // Anything outside <?php tags is echoed automatically
-?>Hello World Again!
+?>
+Hello World Again!
 <?php
 
 
@@ -47,9 +49,9 @@ $boolean = true;  // or TRUE or True
 $boolean = false; // or FALSE or False
 
 // Integers
-$int1 = 19;   // => 19
-$int2 = -19;  // => -19
-$int3 = 019;  // => 15 (a leading 0 denotes an octal number)
+$int1 = 12;   // => 12
+$int2 = -12;  // => -12
+$int3 = 012;  // => 10 (a leading 0 denotes an octal number)
 $int4 = 0x0F; // => 15 (a leading 0x denotes a hex literal)
 
 // Floats (aka doubles)
@@ -100,6 +102,21 @@ echo 'This string ' . 'is concatenated';
 
 
 /********************************
+ * Constants
+ */
+ 
+// A constant is defined by using define()
+// and can never be changed during runtime!
+
+// a valid constant name starts with a letter or underscore,
+// followed by any number of letters, numbers, or underscores.
+define("FOO",     "something");
+
+// access to a constant is possible by direct using the choosen name
+echo 'This outputs '.FOO;
+
+
+/********************************
  * Arrays
  */
 
@@ -380,9 +397,6 @@ echo $function_name(1, 2); // => 3
  * Includes
  */
 
-/*
-```
-```php
 <?php
 // PHP within included files must also begin with a PHP open tag.
 
@@ -526,6 +540,12 @@ interface InterfaceTwo
     public function doSomethingElse();
 }
 
+// interfaces can be extended
+interface InterfaceThree extends InterfaceTwo
+{
+    public function doAnotherContract();
+}
+
 abstract class MyAbstractClass implements InterfaceOne
 {
     public $x = 'doSomething';
@@ -590,9 +610,6 @@ $cls->myTraitMethod(); // Prints "I have MyTrait"
 // This section is separate, because a namespace declaration
 // must be the first statement in a file. Let's pretend that is not the case
 
-/*
-```
-```php
 <?php
 
 // By default, classes exist in the global namespace, and can