在 PHP 中，类成员函数中的局部数组变量是否可以由类成员变量引用 - In PHP, can the local array variable in class member functions referenced by class member variable?

In PHP, can the local array variable in class member functions referenced by class member variable?

class A {
    public $a;
    public function foo() {
        $b = array("a", "b");   
        $this->a = &$b;
    }
}

会发生什么？

$b array的pointer，当函数foo()退出时，$b消失而数组仍然存在？

如果数组也消失了，$a将失去对它的引用。

谁能为我解释一下？

我想你的意思是这样的：

是的，你可以！在这里，您将array $b指定为对$a的引用并更改$b。然后你输出$a它与更改后的$b相同！

<?php 
    class A {
        public $a;
        function foo() {
            $b = array("a", "b");
            $this->a = &$b;
            $b[] = "c";
            print_r($b);
            unset($b);
            print_r($b);
            print_r($this->a);
        }
        function foo2() {
            print_r($this->a);
        }
    }
    $test = new A();
    $test->foo();
    $test->foo2();
?>

输出：

Array ( [0] => a [1] => b [2] => c ) //$b
Notice: Undefined variable: b in C:'xampp'htdocs'Testing'index.php on line 27  //after unset $b
Array ( [0] => a [1] => b [2] => c )  //$a from the function foo
Array ( [0] => a [1] => b [2] => c )  //$a from the function foo2

评论后更新：

(带全局变量(

<?php
    global $c;
    $c = 42;
    $d = &$c;
    $c = 2;
    unset($c);    
    echo $d;

?>

输出：