Use the object returned by simplexml_load_string ($ xml_str) to access a non-existent attribute. empty is true.

The {code...} game property does not exist, but var_dump has a result. why?

$ Xml_str = <
          
   CNY
           
   SUCCESS
           
   NATIVE
       EOT; $ obj = simplexml_load_string ($ xml_str); var_dump ($ obj-> game); if (empty ($ obj-> game) {echo 'Empty ';} else {echo "not empty ";}
  

The game attribute does not exist, but var_dump has a result. why?

Reply content:

$ Xml_str = <
          
   CNY
           
   SUCCESS
           
   NATIVE
       EOT; $ obj = simplexml_load_string ($ xml_str); var_dump ($ obj-> game); if (empty ($ obj-> game) {echo 'Empty ';} else {echo "not empty ";}
  

The game attribute does not exist, but var_dump has a result. why?

AlthoughgameThe property does not exist, but it is called when the property is obtained directly.SimpleXMLElementMagic method__get()This method returns an empty object andvar_dumpPrinted.
Howeverempty()It should be true. why is it false?
Becauseempty()It is not a direct Boolean judgment,empty($var) === isset($var) && $varSo we will callSimpleXMLElementMagic method__isset(), And__isset()The returned property does not exist.__get()It is automatically skipped.

BecausesimplexmlelementInternal ImplementationsetterAndgetter, Just like a magic method__set()And__get(),