【解迷糊】关于PHP的extract()函数提取出的变量的作用域问题

class Test
{
    public function dosome()
    {
        $arr = [‘x‘ => ‘xing‘, ‘y‘ => ‘ya‘];
        extract($arr);
    }

    public function get()
    {
        return $x;
    }
}

$test = new Test();
$test->dosome();
$a = $test->get();
echo $a;  //无法打印

$arr = [‘x‘ => ‘xing‘, ‘y‘ => ‘ya‘];
if (true) {
    extract($arr);
}
echo $x;  //可以打印

function test1()
{
    $arr = [‘x‘ => ‘xing‘, ‘y‘ => ‘ya‘];
    extract($arr);
}

test1();
echo $x;   //无法打印

$arr = [‘x‘ => ‘xing‘, ‘y‘ => ‘ya‘];
extract($arr);
echo $x;   //可以打印