# New in PHP 7.3
- Released on December 6, 2018
- Trailing commas are now allowed in function calls
- Improvements to the Heredoc syntax makes it more flexible to use
array_key_lastare two new array helper functions
PHP 7.2 added a warning when counting uncountable objects.
is_countable function can help prevent this warning.
$count = is_countable($variable) ? count($variable) : null;
These two functions basically do what the name says.
$array = [ 'a' => '…', 'b' => '…', 'c' => '…', ]; array_key_first($array); // 'a' array_key_last($array); // 'c'
The original RFC also proposed
but these were voted against by the majority of people.
Another idea for
array_last was proposed which would return a tuple
[$key => $value],
but opinions were mixed.
For now we only have two functions to get the first and last key of an array.
# Flexible Heredoc syntax rfc
Heredoc can be a useful tool for larger strings, though they had an indentation quirk in the past.
// Instead of this: $query = <<<SQL SELECT * FROM `table` WHERE `column` = true; SQL; // You can do this: $query = <<<SQL SELECT * FROM `table` WHERE `column` = true; SQL;
This is especially useful when you're using Heredoc in an already nested context.
The whitespaces in front of the closing marker will be ignored on all lines.
An important note: because of this change, some existing Heredocs might break, when they are using the same closing marker in their body.
$str = <<<FOO abcdefg FOO FOO; // Parse error: Invalid body indentation level in PHP 7.3
# Trailing commas in function calls rfc
What was already possible with arrays, can now also be done with function calls. Note that it's not possible in function definitions!
$compacted = compact( 'posts', 'units', );
# Better type error reporting
TypeErrors for integers and booleans used to print out their full name,
it has been changed to
bool, to match the type hints in the code.
Argument 1 passed to foo() must be of the type int/bool
In comparison to PHP 7.2:
Argument 1 passed to foo() must be of the type integer/boolean
# JSON errors can be thrown rfc
Previously, JSON parse errors were a hassle to debug.
The JSON functions now accept an extra option to make them throw an exception on parsing errors.
This change obviously adds a new exception:
json_encode($data, JSON_THROW_ON_ERROR); json_decode("invalid json", null, 512, JSON_THROW_ON_ERROR); // Throws JsonException
While this feature is only available with the newly added option, there's a chance it'll be the default behaviour in a future version.
list reference assignment rfc
list() and its shorthand
 syntax now support references.
$array = [1, 2]; list($a, &$b) = $array; $b = 3; // $array = [1, 3];
# Undefined variables in
Undefined variables passed to
compact will be reported with a notice, they were previously ignored.
$a = 'foo'; compact('a', 'b'); // Notice: compact(): Undefined variable: b
# Case-insensitive constants rfc
There were a few edge cases were case-insensitive constants were allowed. These have been deprecated.
# Same site cookie rfc
This change not only adds a new parameter,
it also changes the way the
session_set_cookie_params functions work in a non-breaking manner.
Instead of one more parameters added to already huge functions, they now support an array of options, whilst still being backwards compatible. An example:
bool setcookie( string $name [, string $value = "" [, int $expire = 0 [, string $path = "" [, string $domain = "" [, bool $secure = false [, bool $httponly = false ]]]]]] ) bool setcookie ( string $name [, string $value = "" [, int $expire = 0 [, array $options ]]] ) // Both ways work.
# PCRE2 migration rfc
PCRE — short for "Perl Compatible Regular Expressions" — has been updated to v2.
The migration had a focus on maximum backwards compatibility, though there are a few breaking changes. Be sure to read the RFC to know about them.
# String search functions README
You can no longer pass a non-string needle to string search functions. These are the affected functions:
strpos() strrpos() stripos() strripos() strstr() strchr() strrchr() stristr()
# MBString updates README
MBString is PHP's way of handling complex strings.
This module has received some updates in this version of PHP.
You can read about it here.
# Several deprecations rfc
Several small things have been deprecated, there's a possibility errors can show up in your code because of this.
- String search functions with integer needle
- Defining a free-standing
Please refer to the RFC for a full explanation of each deprecation.