1、方法一:
functionfoo(&$bar){
$bar.="andsomethingextra";
}
$str="ThisisaString,";
foo($str);
echo$str;//output:ThisisaString,andsomethingextra
echo"<br>";

2、方法二:
functionfoo1($bar){
$bar.="andsomethingextra";
}
$str="ThisisaString,";
foo1($str);
echo$str;//output:ThisisaString,
echo"<br>";
foo1(&$str);
echo$str;//output:ThisisaString,andsomethingextra
?>