PHP 8.0 废弃的功能

PHP 核心中废弃的功能

  • 如果带有默认值的参数后面跟着一个必要的参数,那么默认值就会无效。这在 PHP 8.0.0 中已被废弃,通常可以通过删除默认值,不影响现有功能:

    function test($a = [], $b) {} // 之前
    function test($a$b) {}      // 之后

    这条规则的一个例外是 Type $param = null 形式的参数,其中 null 的默认值使得类型隐式为空。这种用法仍然是允许的,但仍建议使用显式可空类型。

    function test(A $a null$b) {} // 旧写法,仍可用
    function test(?A $a$b) {}       // 推荐写法

  • 参数 exclude_disabled 不能设置为 false 来调用 get_defined_functions(),该参数已被废弃,不再起作用。 get_defined_functions() 绝不会再包含禁用的函数。



libxml_disable_entity_loader() has been deprecated. As libxml 2.9.0 is now required, external entity loading is guaranteed to be disabled by default, and this function is no longer needed to protect against XXE attacks, unless the (still vulnerable). LIBXML_NOENT is used. In that case, it is recommended to refactor the code using libxml_set_external_entity_loader() to suppress loading of external entities.


Standard Library

  • Sort comparison functions that return true or false will now throw a deprecation warning, and should be replaced with an implementation that returns an integer less than, equal to, or greater than zero.

    // Replace
    usort($arrayfn($a$b) => $a $b);
    // With
    usort($arrayfn($a$b) => $a <=> $b);


  • Using an empty file as ZipArchive is deprecated. Libzip 1.6.0 does not accept empty files as valid zip archives any longer. The existing workaround will be removed in the next version.

  • The procedural API of Zip is deprecated. Use ZipArchive instead. Iteration over all entries can be accomplished using ZipArchive::statIndex() and a for loop:

    // iterate using the procedural API
    while (
    $entry zip_read($zip)) {

    // iterate using the object-oriented API
    assert($zip instanceof ZipArchive);
    for (
    $i 0$entry $zip->statIndex($i); $i++) {