DOMAttr::isId()
(PHP 5, PHP 7)
Checks if attribute is a defined ID
说明
public DOMAttr::isId(void): bool
This function checks if the attribute is a defined ID.
According to the DOM standard this requires a DTD which defines the attribute ID to be of type ID. You need to validate your document with DOMDocument::validate orDOMDocument::validateOnParsebefore using this function.
返回值
成功时返回TRUE
,或者在失败时返回FALSE
。
范例
Example #1 DOMAttr::isId()Example
<?php $doc = new DomDocument; // We need to validate our document before refering to the id $doc->validateOnParse = true; $doc->Load('book.xml'); // We retrieve the attribute named id of the chapter element $attr = $doc->getElementsByTagName('chapter')->item(0)->getAttributeNode('id'); var_dump($attr->isId()); // bool(true) ?>