php5 值赋值与引述赋值

php5 值赋值与引用赋值
值赋值――2个变量有各自的内存，互不影响

$str1 = "wang";
$str2 = $str1;
$str1 = "zhang";
echo $str2; // wang

$i = "zhao";
$j = "wang";
$j = &$i;

echo $j; // zhao

$j = "hello,$j";
echo $j; //hello,zhao
echo "
";
echo $i; //hello,zhao