Note that using Incrementing/Decrementing operators on string is legal
<?php
$str = "";
echo ++$str; // output: 1
?>
Other changes
Notices and warnings on arithmetic with invalid strings
New E_WARNING and E_NOTICE errors
have been introduced when invalid strings are coerced using operators
expecting numbers (+ -
* / **
% << >>
| & ^) or their
assignment equivalents. An E_NOTICE is emitted when the
string begins with a numeric value but contains trailing non-numeric
characters, and an E_WARNING is emitted when the string
does not contain a numeric value.
<?php
'1b' + 'something';The above example will output:
Notice: A non well formed numeric value encountered in %s on line %d Warning: A non-numeric value encountered in %s on line %d
Warn on octal escape sequence overflow
Previously, 3-octet octal string escape sequences would overflow silently.
Now, they will still overflow, but E_WARNING will be
emitted.
<?php
var_dump("\500");The above example will output:
Warning: Octal escape sequence overflow \500 is greater than \377 in %s on line %d string(1) "@"
Inconsistency fixes to $this
Whilst $this is considered a special variable in PHP, it
lacked proper checks to ensure it wasn't used as a variable name or
reassigned. This has now been rectified to ensure that
$this cannot be a user-defined variable, reassigned to a
different value, or be globalised.
Session ID generation without hashing
Session IDs will no longer be hashed upon generation. With this change brings about the removal of the following four ini settings:
-
session.entropy_file -
session.entropy_length -
session.hash_function -
session.hash_bits_per_character
And the addition of the following two ini settings:
-
session.sid_length- defines the length of the session ID, defaulting to 32 characters for backwards compatibility) -
session.sid_bits_per_character- defines the number of bits to be stored per character (i.e. increases the range of characters that can be used in the session ID), defaulting to 4 for backwards compatibility
Changes to INI file handling
-
precision -
If the value is set to -1, then the dtoa mode 0 is used. The default value is still 14.
-
serialize_precision -
If the value is set to -1, then the dtoa mode 0 is used. The value -1 is now used by default.
-
gd.jpeg_ignore_warning -
The default of this php.ini setting has been changed to 1, so by default libjpeg warnings are ignored.
-
opcache.enable_cli -
The default of this php.ini setting has been changed to 1 (enabled) in PHP 7.1.2, and back to 0 (disabled) in PHP 7.1.7.
Session ID generation with a CSPRNG only
Session IDs will now only be generated with a CSPRNG.
More informative TypeError messages when null is allowed
TypeError exceptions for arg_info type checks will
now provide more informative error messages. If the parameter type or return
type accepts null (by either having a default value of null or being a
nullable type), then the error message will now mention this with a message
of "must be ... or null" or "must ... or be null."
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