Segmentation Fault

[Saad Bin Ahmed]

Hello,

I got segmentation fault error due to problem in following code. If somebody knows how can I write it another way then please share it.

const DOMElement* netElement = (DOMElement*) rootNode->getElementsByTagName(XMLString::transcode("Net" ))->item(0);

When I removed ->item(0) at the the end of above mentioned code then segmentation error removed but program Aborted during execution.

So, in both above mentioned situations please tell me how can I handle this type of situation?

Thanks in advance.

[Banfa]

Perhaps there are no elements with the name "Net", getElementsBytagname would return NULL and you would be dereferencing a NULL pointer.

Do not chain your method calls like this unless you can be absolutely certain that they are going to return a valid result; which generally speaking you never can be.

[Saad Bin Ahmed]

I am giving xml file as an input to this program. The statement shows above is use to read xml Tags, Net is a Tag name and it contains value.

[Banfa]

Is the tag name really "Net" or is it "net" or some other case difference. XML is case sensitive.

Regardless getElementsByTagName returning NULL is the most likely cause and as I said would should not chain calls you are not 100% sure will work.

Instead try

DOMNodeList *nodeList = rootNode->getElementsByTagName(XMLString::transcode("Net");
 
if (nodeList != NULL)
{
    const DOMElement* netElement = (DOMElement*) nodeList->item(0);
}
else
{
    // Output an error message
}
 

Then you can start properly diagnosing your problem.