PHP5.4的变化关注---What has changed in PHP 5.4.x(转)

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发布时间：2019-06-18

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Most improvements in PHP 5.4.x have no impact on existing code. There are a and that should be considered, and code should be tested before switching PHP versions in production environments.

1. Backward Incompatible Changes ：一些内容将不兼容

1)不再支持安全模式，

2) 移除魔术引用，

3) 移除全局变量php.ini设置，

4) 移除（如

call_user_func_array('function', array(&$a) 不支持)

5)break/continue 不接受参数，但保留接受静态参数

6)必须设置时区timezone

7) 注意非数字数组键值详看:

8) 数组转字符串提示

E_NOTICE

level error

8) 使用超全局变量做函数参数将导致致命错误

 function foo($_GET, $_POST) {}   
//在5.3是没问题的.  
//php5.4出现:Fatal error: Cannot re-assign auto-global variable _GET in /opt/php-5.4.0/test.php on line 4  

Although most existing PHP 5 code should work without changes, please take note of some backward incompatible changes:

is no longer supported. Any applications that rely on safe mode may need adjustment, in terms of security.

has been removed. Applications relying on this feature may need to be updated, to avoid security issues. and now always return FALSE. raises an E_CORE_ERROR level error.

The and php.ini directives have been removed.

has been removed.

The and statements no longer accept variable arguments (e.g., break 1 + foo() * $bar;). Static arguments still work, such as break 2;.

In the , the timezone can no longer be set using the TZ environment variable. Instead you have to specify a timezone using the php.ini option or function. PHP will no longer attempt to guess the timezone, and will instead fall back to "UTC" and issue a E_WARNING.

Non-numeric string offsets - e.g. $a['foo'] where $a is a string - now return false on and true on , and produce a E_WARNING if you try to use them. Offsets of types double, bool and null produce a E_NOTICE. Numeric strings (e.g. $a['2']) still work as before. Note that offsets like '12.3' and '5 foobar' are considered non-numeric and produce a E_WARNING, but are converted to 12 and 5 respectively, for backward compatibility reasons. Note: Following code returns different result. $str='abc';var_dump(isset($str['x'])); // false for PHP 5.4 or later, but true for 5.3 or less

Converting an array to a string will now generate an E_NOTICE level error, but the result of the cast will still be the string "Array".

Turning NULL, FALSE, or an empty string into an object by adding a property will now emit an E_WARNING level error, instead of E_STRICT.

Parameter names that shadow super globals now cause a fatal error. This prohibits code like function foo($_GET, $_POST) {}.

The Salsa10 and Salsa20 have been removed.

now returns array() instead of FALSE when two empty arrays are provided as parameters.

If you use with asian character sets, it works like - this has always been the case in previous versions of PHP, but now an E_STRICT level error is emitted.

The following keywords are now , and may not be used as names by functions, classes, etc.

callable

The following functions have been removed from PHP:

, and .

The aliases , , , , , , , mysqli::client_encoding() and mysqli_stmt::stmt().

2. New features 新功能

1）

特性的功能相当使一个类可以存在两个父类。在php5.4之前，一个类不能继承两个父类。

2）数组可以类似c/c++写法

3）Class::{expr}() 这个写法有点迷糊

4）支持二进制数值，即二进制直接写赋值给变量：

$bin  = 0b1101;  
echo $bin;  
 //13  

而不必使用bin2dec转换成十进制

想看大鸟：

5）

6）php5.4可以编译成命令行模式的server

PHP 5.4.0 offers a wide range of new features:

Support for has been added.

Short array syntax has been added, e.g. $a = [1, 2, 3, 4]; or $a = ['one' => 1, 'two' => 2, 'three' => 3, 'four' => 4];.

Function array dereferencing has been added, e.g. foo()[0].

now support $this.

<?= is now always available, regardless of the php.ini option.

Class member access on instantiation has been added, e.g. (new Foo)->bar().

Class::{expr}() syntax is now supported.

Binary number format has been added, e.g. 0b001001101.

Improved parse error messages and improved incompatible arguments warnings.

The session extension can now track the of files.

Built-in development .

Changes in SAPI modules

A new SAPI module named cli-server is now available.

Added CLI option --rz which shows information of the named Zend extension.

Added shortcut #inisetting=value to change php.ini settings at run-time in interactive readline CLI

Added apache compatible functions: , , and for FastCGI SAPI.

PHP-FPM: Added the process.max setting, to control the number of processes that FPM can fork.

3 . Deprecated features in PHP 5.4.x 弃用的功能

Deprecated functions:

4. Changed Functions 变化的自带函数

Several functions were given new, optional parameters in PHP 5.4:

PHP Core:

Added the optional limit parameter to and , to limit the amount of stack frames returned.

now works properly for symbolic links on Windows Vista or later. Earlier systems do not support symbolic links.

OpenSSL:

Added a no padding option to the and functions.

Intl:

and now take two extra parameters, one indicating the variant (IDNA 2003 or UTS #46) and another, passed by reference, to return details about the operation in case UTS #46 is chosen.

5. New Functions 新增的函数

HP 5.4 introduced some new functions:

PHP Core:

6 . New Classes and Interfaces 新增的类和接口

The following classes were introduced in PHP 5.4.0:

7. New Methods 新增的方法

Several new methods were introduced in 5.4.0:

SplQueue::serialize()

SplQueue::unserialize()

SplStack::serialize()

SplStack::unserialize()

SplTempFileObject::fputcsv()

PDO::newRowset()

8. Removed Extensions 移除扩展sqlite

These extensions have been moved to PECL and are no longer part of the PHP distribution. The PECL package versions of these extensions will be created according to user demand.

- Note that ext/sqlite3 and ext/pdo_sqlite are not affected

9 .Other changes to extensions 修改的扩展

Changes in extension behavior, and new features:

- now implements

- Removed support for linking with MySQL client libraries older than 4.1

The MySQL extensions , and use as the default library now. It is still possible to use libmysql by specifying a path to the configure options.

- Added named pipes support

10. New Global Constants 新增的全局常量

PHP Core:

ENT_DISALLOWED

ENT_HTML401

ENT_HTML5

ENT_SUBSTITUTE

ENT_XML1

ENT_XHTML

IPPROTO_IP

IPPROTO_IPV6

IPV6_MULTICAST_HOPS

IPV6_MULTICAST_IF

IPV6_MULTICAST_LOOP

IP_MULTICAST_IF

IP_MULTICAST_LOOP

IP_MULTICAST_TTL

MCAST_JOIN_GROUP

MCAST_LEAVE_GROUP

MCAST_BLOCK_SOURCE

MCAST_UNBLOCK_SOURCE

MCAST_JOIN_SOURCE_GROUP

MCAST_LEAVE_SOURCE_GROUP

CURLOPT_MAX_RECV_SPEED_LARGE

CURLOPT_MAX_SEND_SPEED_LARGE

LIBXML_HTML_NODEFDTD

LIBXML_HTML_NOIMPLIED

LIBXML_PEDANTIC

OPENSSL_CIPHER_AES_128_CBC

OPENSSL_CIPHER_AES_192_CBC

OPENSSL_CIPHER_AES_256_CBC

OPENSSL_RAW_DATA

OPENSSL_ZERO_PADDING

PHP_OUTPUT_HANDLER_CLEAN

PHP_OUTPUT_HANDLER_CLEANABLE

PHP_OUTPUT_HANDLER_DISABLED

PHP_OUTPUT_HANDLER_FINAL

PHP_OUTPUT_HANDLER_FLUSH

PHP_OUTPUT_HANDLER_FLUSHABLE

PHP_OUTPUT_HANDLER_REMOVABLE

PHP_OUTPUT_HANDLER_STARTED

PHP_OUTPUT_HANDLER_STDFLAGS

PHP_OUTPUT_HANDLER_WRITE

PHP_SESSION_ACTIVE

PHP_SESSION_DISABLED

PHP_SESSION_NONE

STREAM_META_ACCESS

STREAM_META_GROUP

STREAM_META_GROUP_NAME

STREAM_META_OWNER

STREAM_META_OWNER_NAME

STREAM_META_TOUCH

ZLIB_ENCODING_DEFLATE

ZLIB_ENCODING_GZIP

ZLIB_ENCODING_RAW

U_IDNA_DOMAIN_NAME_TOO_LONG_ERROR

IDNA_CHECK_BIDI

IDNA_CHECK_CONTEXTJ

IDNA_NONTRANSITIONAL_TO_ASCII

IDNA_NONTRANSITIONAL_TO_UNICODE

INTL_IDNA_VARIANT_2003

INTL_IDNA_VARIANT_UTS46

IDNA_ERROR_EMPTY_LABEL

IDNA_ERROR_LABEL_TOO_LONG

IDNA_ERROR_DOMAIN_NAME_TOO_LONG

IDNA_ERROR_LEADING_HYPHEN

IDNA_ERROR_TRAILING_HYPHEN

IDNA_ERROR_HYPHEN_3_4

IDNA_ERROR_LEADING_COMBINING_MARK

IDNA_ERROR_DISALLOWED

IDNA_ERROR_PUNYCODE

IDNA_ERROR_LABEL_HAS_DOT

IDNA_ERROR_INVALID_ACE_LABEL

IDNA_ERROR_BIDI

IDNA_ERROR_CONTEXTJ

JSON_PRETTY_PRINT

JSON_UNESCAPED_SLASHES

JSON_NUMERIC_CHECK

JSON_UNESCAPED_UNICODE

JSON_BIGINT_AS_STRING

11. Changes to INI file handling php.ini的设置变化

he following php.ini directives have been removed:

, , and

, , , , , and

The following php.ini directives have been added:

and for CLI SAPI using readline in interactive mode.

to enable the built-in development web server to use ANSI color coding in terminal output.

- specifies how many GET/POST/COOKIE input variables may be accepted.

- to control the new multibyte support.

- This value will be used unless a "declare(encoding=...)" directive appears at the top of the script.

- to check for replaced signal handlers on shutdown.

, , , , ,

- When it's disabled, the POST data is not read (and processed)

- This directive shows the Windows CRT warnings when enabled. These warnings were displayed by default until now.

The following php.ini. directives have been changed:

now defaults to /dev/random or /dev/urandom depending on what has been guessed at compile time.

now defaults to 32.

12. Other changes 别的修改

The default character set for and is now UTF-8, instead of ISO-8859-1. Note that changing your output charset via the configuration setting does not affect htmlspecialchars/htmlentities unless you are passing "" (an empty string) as the encoding parameter to your / calls. Generally we do not recommend doing this because you should be able to change your output charset without affecting the runtime charset used by these functions. The safest approach is to explicitly set the charset on each call to and .

E_ALL now includes E_STRICT level errors in the configuration directive.

now has an OOP API. Functions now return FALSE on every error condition including SNMP-related (no such instance, end of MIB, etc). Thus, in particular, breaks previous behavior of get/walk functions returning an empty string on SNMP-related errors. Multi OID get/getnext/set queries are now supported. Dropped UCD-SNMP compatibility code, consider upgrading to net-snmp v5.3+, Net-SNMP v5.4+ is required for Windows version. In sake of adding support for IPv6 DNS name resolution of remote SNMP agent (peer) is done by extension now, not by Net-SNMP library anymore.