php修改xml文件的方法：首先打开xml文件；然后遍历一下xml文档；接着对xml文件内容进行重新赋值；最后保存文件即可。
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PHP 修改和删除XML内容的原理和方法
例如：
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example.xml
<?xml version="1.0" encoding="utf-8"?><root>
<book id="1">
<title>title1</title>
</book>
<book id="2">
<title>title2</title>
</book>
<book id="3">
<title>title3</title>
</book>
<book id="4">
<title>title4</title>
</book>
<book id="5">
<title>title5</title>
</book></root>首先遍历一下该xml文档
<?php
$doc = new DOMDocument();
$doc->load('example.xml');
$books = $doc -> getElementsByTagName("book");
//遍历
foreach ($books as $book) {
echo $book->getAttribute('id')."-";
echo $book->getElementsByTagName("title")->item(0)->nodeValue;
echo "<br>";
}运行结果为：
1-title1
2-title2
3-title3
4-title4
5-title5
修改：
<?php $doc = new DOMDocument(); $doc->load('example.xml');
$books = $doc -> getElementsByTagName("book");
//遍历
foreach ($books as $book) {
//将id=3的title设置为33333
if($book->getAttribute('id')==3){
echo $book->getAttribute('id')."-";
echo $book->getElementsByTagName("title")->item(0)->nodeValue="33333";
echo "<br>";
}
}
//对文件做修改后，一定要记得重新sava一下，才能修改掉原文件
$doc -> save('example.xml');修改之后为：
<?xml version="1.0" encoding="utf-8"?><root>
<book id="1">
<title>title1</title>
</book>
<book id="2">
<title>title2</title>
</book>
<book id="3">
<title>33333</title>
</book>
<book id="4">
<title>title4</title>
</book>
<book id="5">
<title>title5</title>
</book></root>删除操作：
<?php $doc = new DOMDocument();
$doc->load('example.xml');
$root = $doc -> documentElement;
//根标签
$books = $doc -> getElementsByTagName("book");
//遍历
foreach ($books as $book) {
//将id=4的删除
if($book->getAttribute('id')==4){
$root->removeChild($book);
}
} //对文件做修改后，一定要记得重新sava一下，才能修改掉原文件
$doc -> save('example.xml');删除后的结果为：
<?xml version="1.0" encoding="utf-8"?><root>
<book id="1">
<title>title1</title>
</book>
<book id="2">
<title>title2</title>
</book>
<book id="3">
<title>33333</title>
</book>
<book id="5">
<title>title5</title>
</book></root>
