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: ';
/* 注意保存在内存中的数组绝不会被创建或返回 */
foreach (xrange(1, 9, 2) as $number) {
echo "$number ";
}
?>
以上例程会输出：
Single digit odd numbers: 1 3 5 7 9
try-catch blocks now support a finally block for code that should be run regardless of whether an exception has been thrown or not.
foreach 控制结构现在支持通过 list() 构造将嵌套数组分离到单独的变量。例如：
<?php
$array = [
[1, 2],
[3, 4],
];
foreach ($array as list($a, $b)) {
echo "A: $a; B: $b\n";
}
?>
以上例程会输出：
A: 1; B: 2 A: 3; B: 4
关于 foreach 更深入的文档可参考相关手册页面。
empty() 现在支持传入一个任意表达式，而不仅是一个变量。例如：
<?php
function always_false() {
return false;
}
if (empty(always_false())) {
echo 'This will be printed.';
}
if (empty(true)) {
echo 'This will not be printed.';
}
?>
以上例程会输出：
This will be printed.
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";
?>
以上例程会输出：
Array dereferencing: 1 String dereferencing: P
A 新的密码哈希 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.
The Apache 2.4 handler SAPI is now supported on Windows.
对 GD 扩展做了多方面的改进，包括：
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"
Array dereferencing with defaults for possibly empty sources;
<?php
// string(4) "def2"
$x = ([] ?: ["def1", "def2"])[1];
?>
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));
}
}
}
All the new features are incredible. I had always been waiting for such things to be happened.
Finally, array and string literal dereferencing is here, bless you all!
The array and string dereferencing is awesome! Thanks for this.
Thanks for making "empty" easier to use and for the array dereferencing!!
Thank You for making empty() to support arbitrary expressions!
Great work. Thank you for allowing Lists to return on foreach.