php中simplexml_load_string使用实例

在php中simplexml_load_string() 函数把 XML 字符串载入对象中,下面我来给大家介绍几个简单实例的同时也介绍在使用simplexml_load_string的一些需要注意的事项.

先用一段代码重现一下问题,乍一看,结果很让人费解,代码如下:

<?php  
$string = <<<EOF  
<data>  
<foo><bar>hello</bar></foo>  
<foo><bar>world</bar></foo>  
</data>  
EOF; 
 
$data = simplexml_load_string($string); 
 
print_r($data);  
print_r($data->foo);  
 
?>

SimpleXMLElement Object  
(  
[foo] => Array  
(  
[0] => SimpleXMLElement Object  
(  
[bar] => hello  
)  
[1] => SimpleXMLElement Object  
(  
[bar] => world  
)  
)
)  
SimpleXMLElement Object  
(  
[bar] => hello  
)

明明print_r显示foo是一个有两个bar元素的数组,但是最后却仅仅显示了一个bar元素,原因其实很简单,在如上所示simplexml_load_string的结果里,foo并不是数组,而是一个迭代对象.

可以这样确认,代码如下:

foreach ($data->foo as $v) print_r($v); 
foreach ($data->children() as $v) print_r($v);

看来,print_r或者var_dump之类的表象并不完全可信,假如我们获取的XML数据如下,可以使用curl、fsockopen等方式获取,代码如下:

<?xml version="1.0" encoding="UTF-8" 
<dict num="219" id="219" name="219"> 
 <key>你好</key> 
 <pos></pos> 
 <acceptation>Array；Array；Array；</acceptation> 
 <sent> 
  <orig>Haven&#39;t seen you for a long time. How are you?</orig> 
  <trans>多日不见了，你好吗？</trans> 
 </sent> 
 <sent> 
  <orig>Hello! How are you?</orig> 
  <trans>嘿，你好？</trans> 
 </sent> 
 <sent> 
  <orig>Hello, Brooks!How are you?</orig> 
  <trans>喂，布鲁克斯！你好吗？</trans> 
 </sent> 
 <sent> 
  <orig>Hi, Barbara, how are you?</orig> 
  <trans>嘿，芭芭拉，你好吗？</trans> 
 </sent> 
 <sent> 
  <orig>How are you? -Quite well, thank you.</orig> 
  <trans>你好吗？-很好，谢谢你。</trans> 
 </sent> 
</dict>

经过simplexml_load_string得到如下代码:

SimpleXMLElement Object 
( 
[@attributes] => Array 
( 
[num] => 219 
[id] => 219 
[name] => 219 
) 
 
[key] => 你好www.phprm.com 
[pos] => SimpleXMLElement Object 
( 
) 
 
[acceptation] => Array；Array；Array； 
[sent] => Array 
( 
[0] => SimpleXMLElement Object 
( 
[orig] => Haven't seen you for a long time. How are you? 
[trans] => 多日不见了，你好吗？ 
) 
 
[1] => SimpleXMLElement Object 
( 
[orig] => Hello! How are you? 
[trans] => 嘿，你好？ 
) 
 
[2] => SimpleXMLElement Object 
( 
[orig] => Hello, Brooks!How are you? 
[trans] => 喂，布鲁克斯！你好吗？ 
) 
 
[3] => SimpleXMLElement Object 
( 
[orig] => Hi, Barbara, how are you? 
[trans] => 嘿，芭芭拉，你好吗？ 
) 
 
[4] => SimpleXMLElement Object 
( 
[orig] => How are you? -Quite well, thank you. 
[trans] => 你好吗？-很好，谢谢你。 
) 
 
) 
 
)

我们在PHP语言中可以用以下方法取得我们想要的值,代码如下:

".trim($xmldata->sent[0]->orig); //Haven't seen you for a long time. How are you? 
echo "
".trim($xmldata->key); //你好