既存の PHP 5 のコードのほとんどは変更なしで動作するはずですが、 以下の下位互換性のない変更点については注意しましょう。
<?php
print 10 % 0;
/* Warning: Division by zero in filename on line n */
?>
<?php
class foo {}
$foo = new foo;
print $foo;
/* Catchable fatal error: Object of class foo could
not be converted to string in filename on line n */
?>
<?php
class foo {
public function __toString() {
throw new Exception;
}
}
try {
print new foo;
/* Fatal error: Method foo::__toString() must
not throw an exception in filename on line n */
} catch(Exception $e) {}
?>
<?php
abstract class foo {
abstract static function bar();
/* Strict Standards: Static function foo::bar()
should not be abstract in filename on line n */
}
?>
<?php
/* allow_url_include が OFF (デフォルト) の場合 */
include "data:;base64,PD9waHAgcGhwaW5mbygpOz8+";
/* Warning: include(): URL file-access is disabled
in the server configuration in filename on line n */
?>