DOMAttr::isId
(PHP 5, PHP 7, PHP 8)
DOMAttr::isId — Checks if attribute is a defined ID
說明
public DOMAttr::isId(): 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
or DOMDocument::validateOnParse before using this function.
參數
此函式沒有參數。
返回值
成功時返回 true， 或者在失敗時返回 false。
範例
示例 #1 DOMAttr::isId() Example
<?php
$doc = new DomDocument;
// We need to validate our document before referring 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)
?>