Pavel Nikolov introduces PHP7 and discusses some of the major changes from previous versions of PHP. Key points include: - PHP7 is significantly faster than previous versions and uses less memory. The executor is faster and more efficient. - New features in PHP7 include type declarations, return type declarations, the null coalesce operator, constant arrays, anonymous classes, and converting fatal errors to exceptions. - Under the hood changes include an improved compiler that generates better bytecode, an AST-based parser, and a context-sensitive lexer. - There are some backward compatibility breaks, like changes to how indirect expressions are evaluated and how division by zero errors are handled. The $HTTP_RAW_POST

1. Pavel Nikolov
PHP7: Hello World!

3. Who The Fuck
Is This Guy?
Pavel Nikolov

4. Pavel Nikolov
@pavkatar
CEO at ApiHawk Technologies,
Geek, API Evangelist. iLover,
Developer, Coffee drinker and
just an irregular person
Sofia, Bulgaria

5. Hello World!

6. Version Release Lifetime
Personal Homepage Tools (PHP tools) v.1 June 8, 1995 ~ 2 years
PHPFI (Form Interpreter) v2 November 1997 ~ 1 year
PHP3 June 1998 ~ 2 years
PHP4 May 2000 ~ 4 years
PHP5 July 2004 ~ 11 years
PHP5.3 (PHP 6 - Unicode) June 2009
PHP7 Fall 2015
2015 - 20 Years of PHP

7. PHP7 CHANGES “UNDER THE HOOD”

8. PHP Version 5.3 5.4 5.5 5.6 7
Interations per
second
282544 278205 304330 301689 583975
288611 268948 307818 308273 603583
288517 279900 296669 301989 606468
282384 282060 299921 308735 596079
288162 280692 298747 308003 610696
286300 278374 307043 303139 594547
291027 278703 305950 311487 602184
292292 282226 296287 312770 610380
Average 287480 278639 302096 307011 600989
Percentage faster than previous version
N/A -3.08% 8.42% 1.63% 95.76%
Executor: Faster

9. Executor: Less Memory
32 bit 64 bit
PHP 5.6 7.37 MiB 13.97 MiB
PHP 7.0 3.00 MiB 4.00 MiB
$startMemory = memory_get_usage();
$array = range(1, 100000);
echo memory_get_usage() - $startMemory, " bytesn";

10. PHP7 CHANGES “UNDER THE HOOD”
• Executor: Faster
• Executor: Less memory
• Compiler: Generates better bytecode

11. PHP7 CHANGES “UNDER THE HOOD”
• Executor: Faster
• Executor: Less memory
• Compiler: Generates better bytecode
• Parser: Now based on AST (abstract syntax tree)

12. PHP7 CHANGES “UNDER THE HOOD”
• Executor: Faster
• Executor: Less memory
• Compiler: Generates better bytecode
• Parser: Now based on AST (abstract syntax tree)
• Lexer: Now contex-sensitive with support for semi-reserved words
class Collection {
public function forEach(callable $callback) { /* */ }
public function list() { /* */ }
}

13. PHP7 CHANGES “UNDER THE HOOD”
• Executor: Faster
• Executor: Less memory
• Compiler: Generates better bytecode
• Parser: Now based on AST (abstract syntax tree)
• Lexer: Now contex-sensitive with support for semi-reserved words
PHP5.6:
PHP Parse error: Syntax error, unexpected T_FOREACH, expecting T_STRING on line 2
PHP Parse error: Syntax error, unexpected T_LIST, expecting T_STRING on line 3

14. callable class trait extends implements static abstract final public
protected private const enddeclare endfor endforeach endif endwhile
and global goto instanceof insteadof interface namespace new or xor
try use var exit list clone include include_once throw array print echo
require require_once return else elseif default break continue switch
yield function if endswitch finally for foreach declare case do while as
catch die self parent
This is a list of currently globally reserved words that will become semi-reserved
in case proposed change gets approved:

15. PHP7 CHANGES “UNDER THE HOOD”
Limitation!
It's still forbidden to define a class constant named as class because of the class name resolution ::class:
In practice, it means that we would drop from 64 to only 1 reserved word that affects only class constant names.
class Foo {
const class = 'Foo'; // Fatal error
}
// Fatal error: Cannot redefine class constant Foo::CLASS as it is reserved in %s on line %d

16. New Features
http://php.net/manual/en/migration70.new-features.php

17. PHP7 NEW FEATURES
• Type declarations: bool, float, int, string
i)coercively
ii)strictly - declare(strict_types);
function sumOfInts(int $int, bool $bool, string $string){}

18. PHP7 NEW FEATURES
• Type declarations: bool, float, int, string
i)coercively
ii)strictly - declare(strict_types=1);
• Return type declarations === type_declarations

19. PHP7 NEW FEATURES
• Type declarations: bool, float, int, string
i)coercively
ii)strictly - declare(strict_types);
• Return type declarations === type_declarations
• Null coalesce operator
$username = $_GET['user'] ?? 'nobody';
// This is equivalent to:
$username = isset($_GET['user']) ? $_GET['user'] : 'nobody';

20. PHP7 NEW FEATURES
• Type declarations: bool, float, int, string
i)coercively
ii)strictly - declare(strict_types);
• Return type declarations === type_declarations
• Null coalesce operator
• Spaceship operator <=>

21. PHP7 NEW FEATURES
• Type declarations: bool, float, int, string
i)coercively
ii)strictly - declare(strict_types);
• Return type declarations === type_declarations
• Null coalesce operator
• Spaceship operator <=>
• Constant arrays using define()
<?php
define('ANIMALS', [
'dog',
'cat',
'bird'
]);
echo ANIMALS[1]; // outputs "cat"
?>

22. PHP7 NEW FEATURES
• Type declarations: bool, float, int, string
i)coercively
ii)strictly - declare(strict_types);
• Return type declarations === type_declarations
• Null coalesce operator
• Spaceship operator <=>
• Constant arrays using define()
• Anonymous classes $var = new class implements Logger {
public function log(string $msg) {
echo $msg;
}
};

23. PHP7 NEW FEATURES
• Type declarations: bool, float, int, string
i)coercively
ii)strictly - declare(strict_types);
• Return type declarations === type_declarations
• Null coalesce operator
• Spaceship operator <=>
• Constant arrays using define()
• Anonymous classes
• Filtered unserialize()
// converts all objects into __PHP_Incomplete_Class object except those of MyClass and MyClass2
$data = unserialize($foo, ["allowed_classes" => ["MyClass", "MyClass2"]);

24. PHP7 NEW FEATURES
• Type declarations: bool, float, int, string
i)coercively
ii)strictly - declare(strict_types);
• Return type declarations === type_declarations
• Null coalesce operator
• Spaceship operator <=>
• Constant arrays using define()
• Anonymous classes
• Filtered unserialize()
• Group use declarations
use somenamespace{ClassA, ClassB, ClassC as C};

25. PHP7 NEW FEATURES
• Type declarations: bool, float, int, string
i)coercively
ii)strictly - declare(strict_types);
• Return type declarations === type_declarations
• Null coalesce operator
• Spaceship operator <=>
• Constant arrays using define()
• Anonymous classes
• Filtered unserialize()
• Group use declarations
• Integer division with intdiv()

26. PHP7 NEW FEATURES
• Type declarations: bool, float, int, string
i)coercively
ii)strictly - declare(strict_types);
• Return type declarations === type_declarations
• Null coalesce operator
• Spaceship operator <=>
• Constant arrays using define()
• Anonymous classes
• Filtered unserialize()
• Group use declarations
• Integer division with intdiv()
• Fatal Errors to Exceptions

27. PHP7 NEW FEATURES
• Type declarations: bool, float, int, string
i)coercively
ii)strictly - declare(strict_types);
• Return type declarations === type_declarations
• Null coalesce operator
• Spaceship operator <=>
• Constant arrays using define()
• Anonymous classes
• Filtered unserialize()
• Group use declarations
• Integer division with intdiv()
• Fatal Errors to Exceptions
• Removal of date.timezone Warning

28. PHP7 NEW FEATURES
• Type declarations: bool, float, int, string
i)coercively
ii)strictly - declare(strict_types);
• Return type declarations === type_declarations
• Null coalesce operator
• Spaceship operator <=>
• Constant arrays using define()
• Anonymous classes
• Filtered unserialize()
• Group use declarations
• Integer division with intdiv()
• Fatal Errors to Exceptions
• Removal of date.timezone Warning
• Opcache: opcache.huge_code_pages=1 && opcache.file_cache

29. backward
compatibility
breakshttp://php.net/manual/en/migration70.incompatible.php

30. Old and new evaluation of indirect expressions
Expression PHP 5 interpretation PHP 7 interpretation
$$foo['bar']['baz'] ${$foo['bar']['baz']} ($$foo)['bar']['baz']
$foo->$bar['baz'] $foo->{$bar['baz']} ($foo->$bar)['baz']
$foo->$bar['baz']() $foo->{$bar['baz']}() ($foo->$bar)['baz']()
Foo::$bar['baz']() Foo::{$bar['baz']}() (Foo::$bar)['baz']()

31. foreach no longer a the internal array pointer
<?php
$array = [0, 1, 2];
foreach ($array as &$val) {
var_dump(current($array));
}
?>
Output of the above example in PHP 5:
int(1)
int(2)
bool(false)
Output of the above example in PHP 7:
int(0)
int(0)
int(0)

32. foreach by-reference has improved iteration behaviour ¶
Output of the above example in PHP 5:
int(0)
Output of the above example in PHP 7:
int(0)
int(1)
<?php
$array = [0];
foreach ($array as &$val) {
var_dump($val);
$array[1] = 1;
}
?>

33. Changes to Division By Zero
Output of the above example in PHP 5:
Warning: Division by zero in
%s on line %d
bool(false)
Warning: Division by zero in
%s on line %d
bool(false)
Warning: Division by zero in
%s on line %d
bool(false)
<?php
var_dump(3/0); var_dump(0/0); var_dump(0%0);
?>
Output of the above example in PHP 7:
Warning: Division by zero in %s on line
%d
float(INF)
Warning: Division by zero in %s on line
%d
float(NAN)
PHP Fatal error: Uncaught
DivisionByZeroError: Modulo by zero in
%s line %d

34. $HTTP_RAW_POST_DATA removed
$HTTP_RAW_POST_DATA is no longer available. The php://input stream should be used instead.

35. JSON extension replaced with JSOND ¶
The JSON extension has been replaced with JSOND, causing two minor BC breaks.
Firstly, a number must not end in a decimal point
(i.e. 34. must be changed to either 34.0 or 34).
Secondly, when using scientific notation, the e exponent must not immediately follow a
decimal point (i.e. 3.e3 must be changed to either 3.0e3 or 3e3).

36. Compatibility Check
https://github.com/sstalle/php7cc

37. https://hub.docker.com/_/php/

38. TALK/SMOKE
TIME