如果xml節點不存在，使用simpleXML創建它？

Question

如果xml節點不存在，使用simpleXML創建它？

，當我的print_r這個輸出（）我的XML

Array 
(
[0] => SimpleXMLElement Object 
    (
     [A] => SimpleXMLElement Object 
      (
       [a] => a 
      ) 

     [B] => SimpleXMLElement Object 
      (
       [b] => b 
      ) 

     [C] => SimpleXMLElement Object 
      (
       [c] => SimpleXMLElement Object 
        (
         [c1] => c1 
        ) 

      ) 

     [D] => SimpleXMLElement Object 
      (
       [d] => d 
      ) 

     [E] => SimpleXMLElement Object 
      (
       [e] => SimpleXMLElement Object 
        (
         [e1] => e1 
        ) 

      ) 

    ) 
[1] => SimpleXMLElement Object 
    (
     [A] => SimpleXMLElement Object 
      (
       [a] => a11 
      ) 

     [B] => SimpleXMLElement Object 
      (
       [b] => b11 
      ) 

     [C] => SimpleXMLElement Object 
      (
       [c] => SimpleXMLElement Object 
        (
         [c1] => c11 
        ) 

      ) 

     [D] => SimpleXMLElement Object 
      (
       [d] => d1 
      ) 

     [E] => SimpleXMLElement Object 
      (
       [e] => SimpleXMLElement Object 
        (
         [e1] => e11 
        ) 

      ) 

    ) 

）

我要檢查，如果(node <F><f1>f1<f1></F>)

[F] => SimpleXMLElement Object(
      [f1] => f1 
) 

如果不存在我創建這個節點

ANYBODY可以給的方式我怎樣才能用simpleXML做到這一點？

Answer 1

這是很容易做到：

$xml = '<xml></xml>'; 
$sxml = new SimpleXMLElement($xml); 

if (!isset($sxml->F->f1)) { 
    $sxml->addChild('F')->addChild('f1', 'f1'); 
} 

echo $sxml->asXML(); 

你得到：

<?xml version="1.0"?> 
<xml><F><f1>f1</f1></F></xml>