Php 算法 - 如何在没有 eval 的情况下实现

Question

我有一个类通过使用 words.separated.by.dots 键来保存数据存储/访问数据，它的行为如下所示:

    $object = new MyArray()
    $object->setParam('user.name','marcelo');
    $object->setParam('user.email','some@email.com');

    $object->getParams();

    /*
    array(
        'user' => array(
            'name' => 'marcelo',
            'email' => 'some@email.com'
        )
    );
    */

它正在工作，但是方法 unsetParam() 被可怕地实现了。发生这种情况是因为我不知道如何在没有 eval() 函数的情况下实现这一目标。虽然它有效，但我发现它是一个非常具有挑战性的算法，您可能会发现在没有 eval() 的情况下尝试实现它会很有趣。

class MyArray {
   /**
     * @param string $key
     * @return Mura_Session_Abstract 
     */
    public function unsetParam($key)
    {
        $params = $this->getParams();
        $tmp = $params;
        $keys = explode('.', $key);

        foreach ($keys as $key) {
            if (!isset($tmp[$key])) {
                return $this;
            }
            $tmp = $tmp[$key];
        }

        // bad code!
        $eval = "unset(\$params['" . implode("']['", $keys) . "']);";
        eval($eval);

        $this->setParams($params);
        return $this;
    }
}

测试方法:

public function testCanUnsetNestedParam()
{
    $params = array(
        '1' => array(
            '1' => array(
                '1' => array(
                    '1' => 'one',
                    '2' => 'two',
                    '3' => 'three',
                ),
                '2' => array(
                    '1' => 'one',
                    '2' => 'two',
                    '3' => 'three',
                ),
            )
        ),
        '2' => 'something'
    );

    $session = $this->newSession();
    $session->setParams($params);

    unset($params['1']['1']['1']);
    $session->unsetParam('1.1.1');

    $this->assertEquals($params, $session->getParams());
    $this->assertEquals($params['1']['1']['2'], $session->getParam('1.1.2'));
}

Answer 1

是这个吗？

<?php
$params = array(
    '1' => array(
        '1' => array(
        '1' => array(
            '1' => 'one',
            '2' => 'two',
            '3' => 'three',
        ),
        '2' => array(
            '1' => 'one',
            '2' => 'two',
            '3' => 'three',
        ),
        )
    ),
    '2' => 'something'
    );

function unsetParam( &$array, $paramString ) {
$cur =& $array;
$splitted = explode( ".", $paramString );
$len = count( $splitted ) - 1;

    for( $i = 0; $i < $len; ++$i ) {

        if( isset( $cur[ $splitted[ $i ] ] ) ) {
        $cur =& $cur[ $splitted[ $i ] ];
        }
        else {
        return false;
        }


    }

unset( $cur[ $splitted[$i] ] );


}

unsetParam( $params, "1.1.1");

print_r( $params );

/*
Array
(
    [1] => Array
    (
        [1] => Array
        (
            [2] => Array
            (
                [1] => one
                [2] => two
                [3] => three
            )

        )

    )

    [2] => something
)
*/