分享一個「用 Closure 取得 Class Private Property」的特殊技巧

getProperty.php

<?php
// 用 Closure 取得 Class Private Property
//
// ref: https://ocramius.github.io/blog/accessing-private-php-class-members-without-reflection/
// 比用 reflection 快很多

class Example {
    private $myName;

    public function __construct($name) {
        $this->myName = $name;
    }
}

$ex = new Example('Ken Lin');
$reader = function () { return $this->myName; };
$getMyName = $reader->bindTo($ex, $ex);
echo $getMyName() . PHP_EOL; // 輸出：Ken Lin

// 也可以包成一個 helper function
function getProperty($instance, $property) {
    $value = Closure::bind(function () use ($property) {
        return $this->$property;
    }, $instance, $instance)->__invoke();

    return $value;
}

echo getProperty($ex, 'myName') . PHP_EOL; // 輸出：Ken Lin