PHP 7 - Introduction

What is PHP 7?

PHP 7 is a major release of PHP programming language and is touted to be a revolution in the way web applications can be developed and delivered for mobile to enterprises and the cloud. This release is considered to be the most important change for PHP after the release of PHP 5 in 2004.

PHP 7 - Performance

As per the Zend team, following illustrations show the performance comparison of PHP 7 vs PHP 5.6 and HHVM 3.7 on popular PHP based applications.

Magento 1.9

PHP 7 proves itself more than twice as faster, as compared to PHP 5.6 while executing Magento transactions.

PHP 7 - Environment Setup

Try it Option Online

We have set up the PHP Programming environment on-line, so that you can compile and execute all the available examples online. It gives you confidence in what you are reading and enables you to verify the programs with different options. Feel free to modify any example and execute it online.

PHP 7 - Scalar Type Declarations

In PHP 7, a new feature, Scalar type declarations, has been introduced. Scalar type declaration has two options −

• coercive - coercive is default mode and need not to be specified.
• strict - strict mode has to explicitly hinted.
  

PHP 7 - Return Type Declarations

In PHP 7, a new feature, Return type declarations has been introduced. Return type declaration specifies the type of value that a function should return. Following types for return types can be declared.

• int
• float
• bool
• string
• interfaces
• array
• callable

PHP 7 - Null Coalescing Operator

In PHP 7, a new feature, null coalescing operator (??) has been introduced. It is used to replace the ternary operation in conjunction with isset() function. The Null coalescing operator returns its first operand if it exists and is not NULL; otherwise it returns its second operand.

PHP 7 - Spaceship Operator

In PHP 7, a new feature, spaceship operator has been introduced. It is used to compare two expressions. It returns -1, 0 or 1 when first expression is respectively less than, equal to, or greater than second expression.

PHP 7 - Constant Arrays

Array constants can now be defined using the define() function. In PHP 5.6, they could only be defined using const keyword.

PHP 7 - Anonymous Classes

Anonymous classes can now be defined using new class. Anonymous class can be used in place of a full class definition.

Example

<?php
   interface Logger {
      public function log(string $msg);
   }

PHP 7 - Closure::call()

Closure::call() method is added as a shorthand way to temporarily bind an object scope to a closure and invoke it. It is much faster in performance as compared to bindTo of PHP 5.6.

Example - Pre PHP 7

<?php
   class A {
      private $x = 1;

PHP 7 - Filtered unserialize()

PHP 7 introduces Filtered unserialize() function to provide better security when unserializing objects on untrusted data. It prevents possible code injections and enables the developer to whitelist classes that can be unserialized.

PHP 7 - IntlChar

In PHP7, a new IntlChar class is added, which seeks to expose additional ICU functionality. This class defines a number of static methods and constants, which can be used to manipulate unicode characters. You need to have Intl extension installed prior to using this class.

PHP 7 - CSPRNG

In PHP 7, following two new functions are introduced to generate cryptographically secure integers and strings in a cross platform way.

• random_bytes() − Generates cryptographically secure pseudo-random bytes.
• random_int() − Generates cryptographically secure pseudo-random integers.
  

PHP 7 - Expectations

Expectations are a backwards compatible enhancement to the older assert() function. Expectation allows for zero-cost assertions in production code, and provides the ability to throw custom exceptions when the assertion fails. assert() is now a language construct, where the first parameter is an expression as compared to being a string or Boolean to be tested.

PHP 7 - use Statement

From PHP7 onwards, a single use statement can be used to import Classes, functions and constants from same namespace instead of multiple use statements.

PHP 7 - Error Handling

From PHP 7, error handling and reporting has been changed. Instead of reporting errors through the traditional error reporting mechanism used by PHP 5, now most errors are handled by throwing Error exceptions. Similar to exceptions, these Error exceptions bubble up until they reach the first matching catch block. If there are no matching blocks, then a default exception handler installed with

PHP 7 - Integer Division

PHP 7 introduces a new function intdiv(), which performs integer division of its operands and return the division as int.

PHP 7 - Session Options

From PHP7+, session_start() function accepts an array of options to override the session configuration directives set in php.ini. These options supports session.lazy_write, which is by default on and causes PHP to overwrite any session file if the session data has changed.

PHP 7 - Deprecated Features

Following features are deprecated and may be removed from future releases of PHP.

PHP 4 style constructors

PHP 4 style Constructors are methods having same name as the class they are defined in, are now deprecated, and will be removed in the future. PHP 7 will emit E_DEPRECATED if a PHP 4 constructor is the only constructor defined within a class. Classes implementing a __construct() method are unaffected.

PHP 7 - Removed Extensions & SAPIs

Following Extensions have been removed from PHP 7 onwards −

• ereg
• mssql
• mysql
• sybase_ct