php basic

$a = "a";
$b = &$a;

才是a ， b 指向同一对象，不管ab谁变，他们两个都会变化

注：只有名称变量才可使用  &
$a=&(2+8) 是非法的

<?php
$a = 1;
$b = 2;

function Sum()
{
    global $a, $b;
    $b = $a + $b;
}
Sum();
echo $b;
?>

A second way to access variables from the global scope is to use the special PHP-defined $GLOBALS array. The previous example can be rewritten as:


Example #2 Using $GLOBALS instead of global

<?php
$a = 1;
$b = 2;

function Sum()
{
    $GLOBALS['b'] = $GLOBALS['a'] + $GLOBALS['b'];
}

Sum();
echo $b;
?>