New features
Generators added
Support for generators has been added via the yield keyword. Generators provide an easy way to implement simple iterators without the overhead or complexity of implementing a class that implements the Iterator interface.
A simple example that reimplements the range() function as a generator (at least for positive step values):
<?php
function xrange($start, $limit, $step = 1) {
for ($i = $start; $i <= $limit; $i += $step) {
yield $i;
}
}
echo 'Single digit odd numbers: ';
/*
* Note that an array is never created or returned,
* which saves memory.
*/
foreach (xrange(1, 9, 2) as $number) {
echo "$number ";
}
echo "\n";
?>
Результат выполнения данного примера:
Single digit odd numbers: 1 3 5 7 9
finally keyword added
try-catch blocks now support a finally block for code that should be run regardless of whether an exception has been thrown or not.
New password hashing API
A new password hashing API that makes it easier to securely hash and manage passwords using the same underlying library as crypt() in PHP has been added. See the documentation for password_hash() for more detail.
foreach now supports list()
The foreach control structure now supports unpacking nested arrays into separate variables via the list() construct. For example:
<?php
$array = [
[1, 2],
[3, 4],
];
foreach ($array as list($a, $b)) {
echo "A: $a; B: $b\n";
}
?>
Результат выполнения данного примера:
A: 1; B: 2 A: 3; B: 4
Further documentation is available on the foreach manual page.
empty() supports arbitrary expressions
Passing an arbitrary expression instead of a variable to empty() is now supported. For example:
<?php
function always_false() {
return false;
}
if (empty(always_false())) {
echo "This will be printed.\n";
}
if (empty(true)) {
echo "This will not be printed.\n";
}
?>
Результат выполнения данного примера:
This will be printed.
array and string literal dereferencing
Array and string literals can now be dereferenced directly to access individual elements and characters:
<?php
echo 'Array dereferencing: ';
echo [1, 2, 3][0];
echo "\n";
echo 'String dereferencing: ';
echo 'PHP'[0];
echo "\n";
?>
Результат выполнения данного примера:
Array dereferencing: 1 String dereferencing: P
Class name resolution via ::class
It is possible to use ClassName::class to get a fully qualified name of class ClassName. For example:
<?php
namespace Name\Space;
class ClassName {}
echo ClassName::class;
echo "\n";
?>
Результат выполнения данного примера:
Name\Space\ClassName
OPcache extension added
The Zend Optimiser+ opcode cache has been added to PHP as the new OPcache extension. OPcache improves PHP performance by storing precompiled script bytecode in shared memory, thereby removing the need for PHP to load and parse scripts on each request. See the installation instructions for more detail on enabling and using OPcache.
foreach now supports non-scalar keys
foreach now supports keys of any type. While non-scalar keys cannot occur in native PHP arrays, it is possible for Iterator::key() to return a value of any type, and this will now be handled correctly.
Apache 2.4 handler supported on Windows
The Apache 2.4 handler SAPI is now supported on Windows.
Improvements to GD
Various improvements have been made to the GD extension, these include:
- Flipping support using the new imageflip() function.
- Advanced cropping support using the imagecrop() & imagecropauto() functions.
- WebP read and write support using imagecreatefromwebp() & imagewebp() respectively.
Коментарии
Great work. Thank you for allowing Lists to return on foreach.Yield is awesome... it's starts to look like a real language now ;-)
class myList {
public $list;
public function __construct($list) {
$this->list = $list;
}
public function select(...$keys) {
$keys_array = array_fill_keys($keys, null);
$items = $this->list;
foreach($items as $item) {
yield array_merge($keys_array, array_intersect_key($item, $keys_array));
}
}
}
After PHP 5.5, foreach with reference in arbitrary array does not generate an error:
foreach ([1, 2, 3, 4] as $key => &$value) {
$value = $value . ' R$';
}
before 5.4, will generate "Cannot create references to elements of a temporary array expression"