From Rasmus Lerdorf’s Personal Home
Page in 1994 through Zeev Suraski and Andi Gutmans’ rewritten parser for PHP in
1997, PHP has evolved much to occupy itself a prominent place in web
development industry. Rasmus might not have thought his idea would become this
giant tool. He
hated programming and so decided to create a tool just to reuse the code. But later Suraski and Gutmans, the
Israelites, worked with Rasmus for the public release PHP 3. PHP had gained
momentum thereof and it didn’t take too much time to propagate inside the web
development industry, sooner many frameworks and content management systems
were released based on PHP.
For the production, PHP had released
3.0.x, 4.x.x, 5.x.x and support for PHP 4 and previous versions had been discontinued since December
31, 2007.
Now,
it’s PHP 7 not PHP 6!
PHP made releases constantly with
feature additions. It was during June 11, 2015, PHP 7.0.0 Alpha 1 was released
for experimental usage after PHP 5.6.10. After a debate, with votes favouring
for PHP 7, the first alpha release was made. It was all because PHP 6 existed
as an experimental project and was not moved to production phase. Many articles
and books were released to support the migration of 5.x users to 6.x
environment, in order to avoid disputes, version 7 was adopted.
It was on December 03, 2015 PHP
development team announced the immediate availability of PHP 7.0.0 marking the
start of the new major PHP 7 series.
Super
powered engine
PHP 5.x had been powered with Zend Engine II. PHP 7.0.0 released with
a new version of the Zend Engine - PHPNG
(next generation) and numerous improvements. PHPNG’s significant performance
improvement involves optimized memory usage that ultimately requires fewer
servers for serving the same amount of users which previous versions had been
serving for. With PHPNG, the code will be executed almost 2X faster.
Few benchmarks from Rasmus at Deploying
PHP 7, Brooklyn, November 17, 2015. All statistics recorded with 20 requests
per second and latency at 20.
1. Drupal 8-git
2. Wordpress 4.1.1
3. phpBB 3.1.3
4. MediaWiki 1.24.1
5. Wardrobe CMS 1.2.0
6. Moodle 2.9-dev
New
Features and Additions
With the new release, many features
have been introduced to support the programmers.
1.
Spaceship operator [ <=> ]
Also called as combined comparison operator or three-way
comparison operator used for comparing two operands of any type. It returns
0 when two operands are equal, return 1
when the left operand is greater and returns -1 when the right operand is
greater.
2.
Null coalescing operator [ ?? ]
It is an improved ternary operation with addition of isset() to it. It returns its first operand if it exists and is
not NULL, otherwise it returns its second operand.
3.
Anonymous classes
It is a class without name, helpful
for creating simple and one-off objects. Anonymous classes are extremely
helpful when the class is used only once during an execution. It speeds up the
execution time.
4.
Group use declarations
Classes, functions and constants that are imported from the
same namespace can be grouped together inside a single use statement. This
makes the code cleaner and easier to read.
5.
Generator Improvements
Generators
are introduced in PHP 5.5 that yields
as many values as it needs to instead of returning a value. In PHP 7 generator
too can return values that can be fetched from new Generator::getReturn() method. In addition a generator can delegate
to another generator
6.
Type declarations
PHP 7 gives its developers, scalar and return type declaration. It is a quality enhancer for the code that
adds a return type to the functions as scalar types int, float, string and bool
with optional array type.
7.
Exception Handling improvements
Now with PHP 7, error handling is also improved to support
the developers to handle the exceptions appropriately instead of throwing some
Fatal Errors.
a.
Throwable - Base interface for any object that can
be thrown via a throw statement, including Error and Exception.
b.
Error - Base class for all internal PHP errors.
c.
ArithmeticError - Throws when performing mathematical
operations.
d.
AssertionError - Thrown when an assertion made via
assert() fails.
e.
DivisionByZeroError - Thrown when an attempt is made to
divide a number by zero.
f.
ParseError - Thrown when an error occurs while
parsing PHP code, such as when eval() is called.
g.
TypeError - Error related to functions for
inappropriate arguments passed or return type doesn’t match with the one
declared.
8.
Session options
session_start() now accepts an array of options that override
the session configuration directives normally set in php.ini.
9.
New Functions
Out of many new functions, following are four of them that
can be frequently used:
a.
intdiv() - Integer Division that returns the
integer quotient of the division of dividend by divisor.
b.
random_bytes() - Generates cryptographically secure
pseudo-random bytes
c.
random_int() - Generates cryptographically secure
pseudo-random integers
d.
Generator::getReturn() - Get the return value of a generator
(Generators in PHP 7 returns a value too)
Things
to remember
While it is time for migration of old
users into PHP 7, it is good to know that there are many deprecated functions
dropped completely and many unwanted functions moved to deprecated list. This
step is to clean up the garbage inside PHP! Be aware, while moving the legacy
code to PHP 7 without prior steps, will break your system.
1.
To forget about:
a.
mysql_* functions
The entire mysql extension package has
been removed from PHP 7 so adopt mysqli or PDO.
b.
asp_tags and script PHP tags
Use
only PHP tag.
2.
Time to start avoiding:
a.
PHP 4 style constructors
Usage
of constructor with same name as class name is now deprecated
b.
Static calls to non-static methods
Static
calls to methods that are not declared static are deprecated
c.
password_hash() salt option
Deprecated to prevent developers from
generating their own (usually insecure) salts
3.
Have an eye on these:
a.
list()
i. Assignment
of values starts from left which was previously from right (from last). It is
stated in their log not
to depend on the order since this attempt is just implementation and can change
in the future
ii.
Empty
assignments have been removed
iii.
Cannot
unpack string instead str_split() has to be used
b.
Array assignments with reference
The order of the elements in an array
has changed when those elements have been automatically created by referencing
them in a by reference assignment.
c.
global
Variable of variables can no longer be
used with the global keyword. The curly brace syntax has to be used to emulate
that behaviour
d.
foreach
i.
internal
array pointer
Internal array
pointer is maintained after iterating through foreach
ii.
iteration
behaviour
When iterating by-reference, foreach
will now do a better job of tracking changes to the array made during
iteration. Which means values appended to the array inside the loop will also
be tracked
4.
Suggestions for performance
improvements
b. Avoid performing queries inside the
loop
c. Avoid using wildcards like * in SQL
queries (instead use the appropriate column names) and wherever possible use
SQL functions inside SQL query instead of PHP functions
d. Never trust any user inputs, instead
use filters before processing user inputs
Conclusion
PHP is not a dead language or not a
“developed once and used now” language, it is under constant development
supported by a vibrant open source community. With the new Zend engine - PHPNG,
the performance of the latest release has rocketed up. Even in many test cases,
it has bet its competitor HHVM. Definitely, PHP is immortal!
References
