问题描述
我正在尝试用 php 编写购物车,但在多维数组中获取/设置值时遇到问题.我将当前订单保存在 $_SESSION['basket'] 中.看起来像这样:
I am trying to write a shoping cart in php and I have a problem with get/set values in multidimentional arrays. I keep the current order in $_SESSION['basket']. It looks like that:
[basket] => Array ( [0] => Array ( [pid] => 3 [name] => Camera [price] => 200.99 [quantity] => 1 ) [1] => Array ( [pid] => 5 [name] => Computer [price] => 320.99 [quantity] => 1 [extras] => Array ( [0] => Array ( [pid] => 86 [name] => RAM [price] => 99 [qty] => 1 ) [1] => Array ( [pid] => 98 [name] => CD-ROM [price] => 19.99 [qty] => 1 ) ) ) )
每一项都存储为一个子数组.我有一个函数,它检查给定的项目是否存在于 basket 数组中并返回它的路径.例如,如果我想检查具有 id 98 (CD-Rom) 的产品,该函数返回以下路径:1:extras:1代码>.
Every item is stored as a subarray. I have a function, which checks if a given item exists in the basket array and returns the path to it. For example, if I want to check for a product with id 98 (CD-Rom), the function returns the following path: 1:extras:1.
如果我想在数组中获取或设置一个值,我无法弄清楚如何使用路径.是否可以在不使用 eval() 的情况下构造数组键的路径?我有这些功能:
I cant figure out how to use the path if I want to get or a set a value in the array. Is it possible to construct the path to an array key, without the use of eval()? I have these functions:
function get_val($array, $path, $key) { //some code return eval('return '.$array.$path.$key.';'); }
所以,$price = get_val($_SESSION['basket'], $path, 'price');应该返回 CD-ROM 的价格 (19.99)
So, $price = get_val($_SESSION['basket'], $path, 'price'); should return the price for CD-ROM (19.99)
function set_val($array, $path, $key, $value) { //some code $str = eval(''.$array.$path.$key.';'); $str = $value; }
set_val($_SESSION['basket'], $path, 'price', '30'); 将 CD-ROM 的价格设置为 30.
set_val($_SESSION['basket'], $path, 'price', '30'); will set the price for CD-ROM to 30.
有没有更好的方法来做到这一点?
Is there a better way for doing this?
谢谢.
推荐答案
这是我前段时间微调的代码:
Here you go a code I have finetuned some time ago:
function get_val($array,$path) { for($i=$array; $key=array_shift($path); $i=$i[$key]) { if(!isset($i[$key])) return null; } return $i; } function set_val(&$array,$path,$val) { for($i=&$array; $key=array_shift($path); $i=&$i[$key]) { if(!isset($i[$key])) $i[$key] = array(); } $i = $val; }
看到这个测试示例,我相信这就是你要找的:
See this test example, I believe it is what you are looking for:
$data = array("x"=>array("y"=>array("z"=>"foo"))); echo get_val($data,array("x","y","z")); // foo set_val($data,array("x","y","u"),"bar"); // $data["x"]["y"]["u"] = "bar";