PHP 8 in Visual Studio Code

Author by Jakub Misek
December 11, 2020 6 minutes

PHP 8 represents a big milestone for developers, frameworks, and content management systems like WordPress. It introduces several new language constructs, that are not backward compatible with previous versions of PHP, it deprecates some functions, and there are some new eventual issues you should be aware of.

The Environment

When developing with VS Code, you have to install PHP and Xdebug by yourself. In case you are running Windows and Microsoft Visual Studio, there is our One-Click installer for PHP.

To specify which PHP version should be used by the Visual Studio Code editor, change the VS Code's setting "php.executablePath" to point to the binaries. On Windows, it might be something like:

{
  "php.executablePath": "C:/Program Files (x86)/IIS Express/PHP/v8.0/php.exe",
}

When opening a .php file, you will see several notifications about your PHP version. In the output window and the status bar.

VS Code Status with PHP 8 and Xdebug 3

Named Arguments

Named arguments is a new PHP 8 feature allowing to specify the name of parameter before provided the value. It allows to skip optional parameters, makes the code more readable, and also it works great with argument unpacking and call_user_func_array() function.

named arguments in vs code

In Visual Studio Code, it is well understood by code completion, tool-tips, and code analysis as well. Misspelled arguments are underlined, since it would cause a fatal error in run time, type mismatches are checked as well. In case, user doesn't have PHP 8, any use of named arguments is underlined as well, since it is considered a syntax error on PHP 7.4 or older.

unknown argument name

Code completion provides available arguments including the detailed tool-tip information with type, default value, and description.

named argument completion

Attributes

Since PHP 8, instead of using PHP documentary comments (PHPDoc) developers can annotate functions, classes, interfaces, traits, properties, constants, and parameters with attributes. The advantage is a cleaner way of annotating things and the direct support in PHP reflection. All the reflection class get ->getAttributes() method which returns an array of ReflectionAttribute instances.

Following depicts the code completion of the attribute "MyAttribute" and then it's arguments $name and $value.

attributes completion

<?php

$attributes = (new ReflectionClass(Grapes::class))->getAttributes();

// or only get attributes with given name
$attributes = (new ReflectionClass(Grapes::class))->getAttributes("MyAttribute");

foreach ($attributes as $myattr) {
    print_r( $myattr->getArguments() ); // get original arguments
    print_r( $myattr->newInstance() ); // instantiate \MyAttribute class
}

Catch, Throw, Null-Safe operator, Match, ..

There are a few nice syntactic sugar enhancements, that might make your code smaller and more readable.

  • catch can be written without the catch variable

catch without variable

  • throw is an expression. Usually you can make use of it as a part of conditions.
  • match construct is like switch but as an expression.
  • constructor properties allows to define a constructor parameter that at the same time defines a class property with the same name initialized implicitly with given value.

throw, match

  • null-safe operator ?-> allows to avoid null checking in expression chains. The operator respects short circuit evaluation rules, and it's especially useful for longer expression chains.

nullsafe operator

The Editor

The Visual Studio Code editor with PHP Tools respects and helps with the new PHP 8 features, including the new Xdebug 3 debugging extension support and other language constructs like the new union type hints and checking for compatibility if you haven't switched to PHP 8 yet and still using the version 7.4. Our integration is getting more updates soon, always keeping up to date with the latest standards.

Jakub Misek