php向后兼容,PHP: 不向后兼容的变更 - Manual

match 现在是一个保留字。

断言(Assertion)失败现在默认抛出异常。如果想要改回之前的行为，可以在 INI 设置中设置

assert.exception=0 。

与类名相同的方法名将不再被当做构造方法。应该使用__construct()

来取代它。

不再允许通过静态调用的方式去调用非静态方法。因此

(real) 和 (unset) 转换已被移除。

The track_errors ini directive has been removed. This

means that php_errormsg is no longer available. The

The ability to define case-insensitive constants has been removed. The third argument to

true.

The ability to specify an autoloader using an

The errcontext argument for custom error handlers has been removed.

foreach or ArrayIterator

should be used instead.

The ability to unbind this from closures that were created from a method,

using Closure::fromCallable() or

The ability to unbind this from proper closures that contain uses of

this has also been removed.

The ability to use

The behavior of key parameter has been made consistent with TypeError.

Any array that has a number n as its first numeric key will use

n+1 for its next implicit key, even if n is

negative.

The default error_reporting level is now E_ALL. Previously it excluded

E_NOTICE and E_DEPRECATED.

display_startup_errors is now enabled by

default.

Using parent inside a class that has no parent will now result in a fatal

compile-time error.

The @ operator will no longer silence fatal errors

(E_ERROR, E_CORE_ERROR,

E_COMPILE_ERROR, E_USER_ERROR,

E_RECOVERABLE_ERROR, E_PARSE). Error handlers that

expect error_reporting to be 0 when @ is used, should be

adjusted to use a mask check instead:

if (error_reporting() ==0) {

return;// Silenced}// ...}// Withfunctionmy_error_handler($err_no,$err_msg,$filename,$linenum) {

if (!(error_reporting() &$err_no)) {

return;// Silenced}// ...}?>

Additionally, care should be taken that error messages are not displayed in production

environments, which can result in information leaks. Please ensure that

display_errors=Off is used in conjunction with error logging.

#[ is no longer interpreted as the start of a comment,

as this syntax is now used for attributes.

Inheritance errors due to incompatible method signatures (LSP violations) will now always

generate a fatal error. Previously a warning was generated in some cases.

The precedence of the concatenation operator has changed relative to bitshifts and addition as

well as subtraction.

Arguments with a default value that resolves to null at runtime will no longer implicitly mark

the argument type as nullable. Either an explicit nullable type, or an explicit null default

value has to be used instead.

A number of warnings have been converted into Error exceptions:

Attempting to write to a property of a non-object. Previously this

implicitly created an stdClass object for null, false and empty strings.

Attempting to append an element to an array for which the PHP_INT_MAX key

is already used.

Attempting to use an invalid type (array or object) as an array key or

string offset.

Attempting to write to an array index of a scalar value.

Attempting to unpack a non-array/Traversable.

Attempting to access unqualified constants which are undefined.

Previously, unqualified constant accesses resulted in a warning and were interpreted as strings.

A number of notices have been converted into warnings:

Attempting to read an undefined variable.

Attempting to read an undefined property.

Attempting to read an undefined array key.

Attempting to read a property of a non-object.

Attempting to access an array index of a non-array.

Attempting to convert an array to string.

Attempting to use a resource as an array key.

Attempting to use null, a boolean, or a float as a string offset.

Attempting to read an out-of-bounds string offset.

Attempting to assign an empty string to a string offset.

Attempting to assign multiple bytes to a string offset will now emit a warning.

Unexpected characters in source files (such as NUL bytes outside of strings) will now result in a

ParseError exception instead of a compile warning.

Uncaught exceptions now go through "clean shutdown", which means that destructors will be called

after an uncaught exception.

The compile time fatal error "Only variables can be passed by reference" has been delayed until

runtime, and converted into an "Argument cannot be passed by reference"

Error exception.

Some "Only variables should be passed by reference" notices have been converted to "Argument

cannot be passed by reference" exception.

The generated name for anonymous classes has changed. It will now include the name of the first

parent or interface:

 ParentClass@anonymousnew class implementsFirstInterface,SecondInterface{};// -> FirstInterface@anonymousnew class {};// -> class@anonymous?>

The name shown above is still followed by a NUL byte and a unique suffix.

Non-absolute trait method references in trait alias adaptations are now required to be

unambiguous:

useT1,T2{funcasotherFunc;

}

functionfunc() {}

}?>

If both T1::func() and T2::func() exist, this code was previously

silently accepted, and func was assumed to refer to T1::func. Now it will generate a

fatal error instead, and either T1::func or T2::func needs to be

written explicitly.

The signature of abstract methods defined in traits is now checked against the implementing class

method:

abstract private functionneededByTrait():string;

}

classMyClass{

useMyTrait;// Error, because of return type mismatch.private functionneededByTrait():int{ return42; }

}?>

Disabled functions are now treated exactly like non-existent functions. Calling a disabled

function will report it as unknown, and redefining a disabled function is now possible.

data:// stream wrappers are no longer writable, which matches the documented

behavior.

The arithmetic and bitwise operators +, -,

*, /, **, %,

<>, &,

|, ^, ~, ++,

-- will now consistently throw a TypeError when one of

the operands is an array, 资源(resource) or non-overloaded object. The only exception to this is

the array + array merge operation, which remains supported.

Float to string casting will now always behave locale-independently.

setlocale(LC_ALL, "de_DE");

$f = 3.14;

echo $f, "\n";

// Previously: 3,14

// Now: 3.14

?>

See NumberFormatter() for ways to customize number formatting.

Support for deprecated curly braces for offset access has been removed.

// Instead of:

$array{0};

$array{"key"};

// Write:

$array[0];

$array["key"];

?>

Applying the final modifier on a private method will now produce a warning unless that method is

the constructor.

If an object constructor

Namespaced names can no longer contain whitespace: While Foo\Bar will be recognized

as a namespaced name, Foo \ Bar will not. Conversely, reserved keywords are now

permitted as namespace segments, which may also change the interpretation of code:

new\x is now the same as constant('new\x'), not

new \x().

Nested ternaries now require explicit parentheses.

Numeric string handling has been altered to be more intuitive and less error-prone. Trailing

whitespace is now allowed in numeric strings for consistency with how leading whitespace is

treated. This mostly affects:

String-to-string comparisons

Type declarations

Increment and decrement operations

The concept of a "leading-numeric string" has been mostly dropped; the cases where this remains

exist in order to ease migration. Strings which emitted an E_NOTICE "A non

well-formed numeric value encountered" will now emit an E_WARNING "A

non-numeric value encountered" and all strings which emitted an E_WARNING "A

non-numeric value encountered" will now throw a

TypeError. This mostly affects:

Arithmetic operations

Bitwise operations

This E_WARNING to TypeError change also affects the

E_WARNING "Illegal string offset 'string'" for illegal string offsets. The

behavior of explicit casts to int/float from strings has not been changed.

Magic Methods will now have their arguments and return types checked if they have them declared.

The signatures should match the following list:

__call(string $name, array $arguments): mixed

__callStatic(string $name, array $arguments): mixed

__clone(): void

__debugInfo(): ?array

__get(string $name): mixed

__invoke(mixed $arguments): mixed

__isset(string $name): bool

__serialize(): array

__set(string $name, mixed $value): void

__set_state(array $properties): object

__sleep(): array

__unserialize(array $data): void

__unset(string $name): void

__wakeup(): void

Declaring a function called assert() inside a namespace is

no longer allowed, and issues E_COMPILE_ERROR.

The