New features

PHP 5.4.0 offers a wide range of new features:

• Support for 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].
• Closures now support $this.
• <?= is now always available, regardless of the short_open_tag php.ini option.
• 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.