===== PHP Versions =====


==== 5.4 ====
[[http://docs.php.net/manual/en/migration54.new-features.php|ref]]

  * Support for [[http://docs.php.net/manual/en/language.oop5.traits.php|traits]] has been added.
  * Short array syntax has been added, e.g. $a = [1, 2, 3, 4]; or $a = ['one' => 1, 'two' => 2, 'three' => 3, 'four' => 4];.
  * Function array dereferencing has been added, e.g. foo()[0].
  * [[http://docs.php.net/manual/en/functions.anonymous.php|Closures]] now support $this.
  * Class member access on instantiation has been added, e.g. (new Foo)->bar().
  * Class::{expr}() syntax is now supported.
  * Binary number format has been added, e.g. 0b001001101.
  * Improved parse error messages and improved incompatible arguments warnings.
  * The session extension can now track the upload progress of files.
  * Built-in development web server in CLI mode
==== 5.5 ====
[[http://docs.php.net/manual/en/migration55.new-features.php|ref]]

  * [[http://docs.php.net/manual/en/language.generators.php|Generators]] added
  * finally keyword added
  * foreach now supports list()
  * empty() supports arbitrary expressions
  * Class name resolution via ::class 


==== 5.6 ====
[[http://docs.php.net/manual/en/migration56.new-features.php|ref]]

  * Constant expressions
  * Variadic functions via ...
  * Argument unpacking via ...
  * Exponentiation via ** 
  * use function and use const

==== 7.0 ====
[[http://docs.php.net/manual/en/migration70.new-features.php|ref]]

  * Scalar type declarations
  * Return type declarations 
  * Null coalescing operator
  * Spaceship operator 
  * Constant arrays using define()
  * Anonymous classes
  * Closure::call() 
  * Expectations
  * Group use declarations 

==== 7.1 ====
http://docs.php.net/manual/en/migration71.new-features.php