PHP 7.0 introduced a new engine and major language changes, including scalar and return type declarations, the null coalescing operator, and anonymous classes. It also brought substantial performance and memory improvements. PHP 7.1 through 7.4 added features such as nullable types, typed properties, and arrow functions, so “PHP 7” refers to a series of releases rather than one fixed feature set.
What changed from PHP 5.6 to PHP 7.0?
PHP 7.0, released in 2015, introduced Zend Engine 3.0. The PHP Development Team announced that PHP 7 was “up to twice as fast as PHP 5.6.” This is a headline release claim, not a guarantee that every application or workload will run twice as fast. The PHP history also highlights reduced memory use, consistent 64-bit support, improved exception handling, and a secure random number generator.
The release refreshed both runtime behavior and day-to-day PHP syntax. Type declarations gave developers ways to state expectations for function inputs and outputs, while operators such as ?? and <=> made common logic more concise.
Which language features arrived in PHP 7.0?
Scalar and return types
Functions and methods can declare scalar parameter types—string, int, float, or bool—and can declare a return type. Scalar declarations are coercive by default. A file can opt into strict scalar handling with declare(strict_types=1); strictness is a per-file setting.
Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Scan for outdated or missing drivers - takes under a minuteDriver Scan →#1 Best Overall
Null coalescing and comparisons
The null coalescing operator, ??, returns its left operand if it exists and is not null; otherwise it returns the fallback. It is useful for the common case previously written with isset() and a ternary:
$name = $_GET['name'] ?? 'Guest';
The spaceship operator, <=>, returns -1, 0, or 1 when the left value compares as less than, equal to, or greater than the right value under PHP’s comparison rules. It is especially useful in comparison callbacks, such as sorting.
Rank #2
Anonymous classes, imports, and generators
An anonymous class, created with new class, lets code instantiate an object without declaring a named class. Grouped use declarations let related classes, functions, or constants share an import statement.
Generators gained return expressions, whose final value can be retrieved with Generator::getReturn(), and delegation through yield from. These additions help structure generator-based code without requiring every value to be yielded directly from one generator.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Other PHP 7.0 changes
- Array constants can be defined with
define(). - Many fatal errors became exceptions, changing how some failures can be handled.
- PHP introduced an abstract syntax tree internally.
- The release announcement included zero-cost assertions among the changes.
What was added in PHP 7.1, 7.2, 7.3, and 7.4?
Several features often associated with PHP 7 arrived after 7.0. If a project targets a particular 7.x release, check that release’s compatibility requirements rather than assuming every PHP 7 feature is available.
| Release | Notable additions and changes |
|---|---|
| PHP 7.1 | Nullable types, void and iterable types, class-constant visibility modifiers, keyed and square-bracket list() syntax, and multi-catch exceptions. |
| PHP 7.2 | object type hints, Argon2 password hashing, the sodium extension, improved numeric-key handling in casts, and removal of mcrypt. |
| PHP 7.3 | Flexible heredoc and nowdoc syntax, migration to PCRE2, mbstring improvements, LDAP controls support, and improved FPM logging. |
| PHP 7.4 | Typed properties, arrow functions, limited return-type covariance and argument contravariance, array unpacking, numeric literal separators, weak references, exceptions from __toString(), and opcache preloading. |
Which PHP 7 features are most useful to adopt?
Choose features based on the PHP version your environment supports and the problem you are solving. Type declarations can make interfaces clearer; ?? can simplify fallback logic; and arrow functions can make short callbacks more readable in PHP 7.4. Later additions such as typed properties are unavailable in PHP 7.0, so using them requires a sufficiently recent runtime.
Rank #4
- Use scalar and return types when they clarify a function’s contract, and decide deliberately whether a file should use strict scalar handling.
- Use
??when the intended test is “set and not null”; it is not interchangeable with a truthiness check. - Use
<=>for comparison logic where PHP’s comparison semantics are appropriate. - Adopt later-version syntax only after confirming the minimum PHP version required by every production environment and deployment image.
What should you check before upgrading?
The official PHP 7.0 migration guide organizes compatibility information around backward-incompatible changes, deprecated features, changed and new functions, removed extensions and SAPIs, and other changes. PHP’s guidance is to test code before changing the PHP version in production.
- Read the migration information for the target release. Start with the PHP 7.0 migration guide and review the notes for each later release you plan to use.
- Check language and error behavior. Look for code affected by changed behavior, deprecations, or the conversion of many fatal errors into exceptions; ensure error handling behaves as intended.
- Verify extensions and dependencies. Confirm that required extensions are available for the target runtime and that application dependencies support it. In particular, mcrypt was removed in PHP 7.2.
- Test outside production first. Run the application’s automated tests and exercise important user flows on the intended PHP version. Investigate failures before switching live traffic.
- Review deployment configuration. Check the PHP version in deployment images and runtime configuration, along with the extensions and SAPIs the application relies on, so staging and production do not silently differ.
For the authoritative list of language additions, see the PHP 7.0 new features documentation. Official release notes cover PHP 7.1, PHP 7.2, PHP 7.3, and PHP 7.4.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
