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(PHP 5, PHP 7)
DOMAttr::isId — Checks if attribute is a defined ID
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.
成功时返回 TRUE
, 或者在失败时返回 FALSE
。
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)
?>