DOMAttr->isId()

说明

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() or DOMDocument::validateOnParse before using this function.

返回值

如果成功则返回 TRUE，失败则返回 FALSE。

范例

例子 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) ?>