PHP7: twice as fast, half the memory consumption and… Spaceships!

PHP 7 is out and comes with a lot of improvements, new features and a new version of the Zend Engine. I got your attention probably by mentioning spaceships in the title. So let’s start off with this new feature PHP7 brings us, the Spaceship Operator.
Because having a spaceship is one thing, operating it is another 😉

Known in mathematics and other programming languages as the sign or Sgn function, spaceship operators are used to compare two expressions. Returning 1 when the first is greater than the second, 0 when both are equal and -1 when the first is less than the second.

// Integers
echo 1 <=> 1; // 0
echo 1 <=> 2; // -1
echo 2 <=> 1; // 1

// Floats
echo 1.5 <=> 1.5; // 0
echo 1.5 <=> 2.5; // -1
echo 2.5 <=> 1.5; // 1

// Strings
echo "a" <=> "a"; // 0
echo "a" <=> "b"; // -1
echo "b" <=> "a"; // 1

I’m a big fan of the ternary operator – when used wisely! They greatly improve the readability of simple checks and assignments of variables.
Now a common use case is simplified by the Null calesce operator, checking if a variable "isset". You can even chain them.

// Fetches the value of $_GET['user'] and returns 'nobody'
// if it does not exist.
$username = $_GET['user'] ?? 'nobody';
// This is equivalent to:
$username = isset($_GET['user']) ? $_GET['user'] : 'nobody';

// Coalesces can be chained: this will return the first
// defined value out of $_GET['user'], $_POST['user'], and
// 'nobody'.
$username = $_GET['user'] ?? $_POST['user'] ?? 'nobody';

Other new features include:

• Scalar type declarations
• Return type declarations
• Constant arrays using define()
• Anonymous classes
• Unicode codepoint escape syntax
• Closure::call()
• Filtered unserialize()
• IntlChar
• Expectations
• Group use declarations
• Generator Return Expressions
• Generator delegation
• Integer division with intdiv()
• Session options
• preg_replace_callback_array()
• CSPRNG Functions
• list() can always unpack objects implementing ArrayAccess

Read more about them at php.net.

Zend made a nice infographic of PHP7’s performance improvement benchmark results, which are quite impressive: