(PHP 5, PHP 7)
DOMDocument::createComment — Create new comment node
This function creates a new instance of class DOMComment. 此节点出现在文档中，除非是用诸如 DOMNode->appendChild() 等函数来将其插入。
dataThe content of the comment.
The new DOMComment or FALSE if an error occurred.
To prevent a parser error when the comment string would contain the character sequence "--", do this:
<?php
$CommentString = 'This contains -- some weird -- characters.';
$CommentNode = $DomDocument->createComment(
str_replace('--', '-'.chr(194).chr(173).'-', $CommentString)
);
?>
This will insert a Soft Hyphen in between the two hyphens which will not cause the parser to error out.
Use caution: this function does NOT escape, encode, or otherwise change the contents of the string.
This means that if your string contains two hyphens in a row (--), that will *end* the comment, which can easily create invalid XML when the document is serialized.