Question

我无法将变量分配给$_SESSION数组中的数组。

看起来它正在分配，但是当我在程序结束时执行print_r时，$_SESSION变量看起来没有变化。

这是代码。

<?php
session_start();

print_r($_SESSION[cart_array]);

$NewGroupName="NewGroupName";

foreach($_SESSION[cart_array] as $row) {        

   if ($row['groupId'] == "26141"){
     echo "The initial GroupName is" . $row['GroupName'] . "<br>";

     echo   "The GroupName should be " . $NewGroupName."<br>";

     $row['GroupName']   = $NewGroupName;
     echo   "The actual GroupName is " . $row['GroupName']."<br>";


   }
}
print_r($_SESSION[cart_array]);
?>

第一个print_r：

Array ( [0] => Array ( [groupId] => 26141 [GroupName] => 'Crystal Farm - Ten Yard Case Pack' [StylePatternColor] => A-CF-10 [Price] => 5.65 [StandardPutUp] => 320 [Discount] => 0 [DiscountText] => [StkUnit] => YDS [ListPrice] => 5.65 [Quantity] => 1 [PromiseDate] => 10/01/2017 [DoNotShipBefore] => 02-01-2017 [ColorName] => 32 Ten Yard Bolts [PatternName] => [SKUDescription] => [KitPerYardDiscount] => False [KitPerYardDiscountText] => False [Kit] => False ) [] => Array ( [DoNotShipBefore] => ) )

这种分配似乎有效：

The initial GroupName is'Crystal Farm - Ten Yard Case Pack'
The GroupName should be NewGroupName
The actual GroupName is NewGroupName

但是，最终的print_r显示我们没有更改GroupName的值。

 Array ( [0] => Array ( [groupId] => 26141 [GroupName] 
=> 'Crystal Farm - Ten Yard Case Pack' [StylePatternColor] 
=> A-CF-10 [Price] 
=> 5.65 [StandardPutUp] 
=> 320 [Discount] 
=> 0 [DiscountText] 
=> [StkUnit] 
=> YDS [ListPrice] 
=> 5.65 [Quantity] 
=> 1 [PromiseDate] 
=> 10/01/2017 [DoNotShipBefore] => 02-01-2017 [ColorName] 
=> 32 Ten Yard Bolts [PatternName] => [SKUDescription] => [KitPerYardDiscount] => False [KitPerYardDiscountText] => False [Kit] => False ) [] 
=> Array ( [DoNotShipBefore] => ) )

任何帮助都将不胜感激。

Answer 1

您不能在代码中的任何位置更改$_SESSION。 foreach只公开每个元素的副本。您可以使用引用&更改它：

foreach($_SESSION['cart_array'] as &$row) {

另请注意，字符串索引$_SESSION['cart_array']需要引号。如果您有错误报告，您会看到通知 未定义常量：cart_array。

Answer 2

来自php.net：

为了能够直接修改循环中的数组元素，在$ value之前加上＆amp ;.在这种情况下，该值将通过引用分配。

<?php
$arr = array(1, 2, 3, 4);
foreach ($arr as &$value) {
    $value = $value * 2;
}
// $arr is now array(2, 4, 6, 8)
unset($value); // break the reference with the last element
?>

为什么$ _SESSION数组没有被更改？

2 个答案: