Question

我的代码：情景1

$newarray = array();

foreach($rows as $k => $v) 
    {
           $newarray[$k] = $v;
           $newarray['newitem'] = 'Add this to existing object';   
    }
echo json_encode($newarray);

我也试过这个：情景2

$newarray = array();

foreach($rows as $k => $v) 
    {
           $newarray[$k] = $v;
           $newarray[$k]['newitem'] = 'Add this to existing object';   
    }
echo json_encode($newarray);

在方案1中，仅在第一个对象之后添加键值对。它没有循环。在方案2中，我得到HTTP ERROR 500

我在这里做错了什么？

更新

现有产出：

[{"pid":"123","date":"2016-08-23 08:08:40","post_title":"AHHH"},{"pid":"223","date":"2016-08-23 08:08:40","post_title":"wwwwAHHH"},{"pid":"223","date":"2016-08-23 08:08:40","post_title":"xxxAHHH"}]

必需输出：

[{"pid":"123","date":"2016-08-23 08:08:40","post_title":"AHHH","newkey":"new value1"},{"pid":"223","date":"2016-08-23 08:08:40","post_title":"wwwwAHHH","newkey":"new value2"},{"pid":"223","date":"2016-08-23 08:08:40","post_title":"xxxAHHH","newkey":"new value3"}]

Answer 1

您可以创建一个包含所需内容的临时数组，然后将其添加到newarray中，以创建临时数组，添加新数据和现有数据，然后将其添加到newarray

$newarray = array();
foreach($rows as $k => $v) 
{
    $t = $v;
    $t['newitem'] = 'Add this to existing object';
    $newarray[$k] = $t;
}
echo json_encode($newarray);

编辑：

现在我知道$rows中的JSON字符串是什么，这是你想做的事情。您不能通过JSON字符串进行操作，必须先将其转换为PHP数据结构，然后再添加新数据，然后将其转换回JSON字符串

$rows = '[{"pid":"123","date":"2016-08-23 08:08:40","post_title":"AHHH"},{"pid":"223","date":"2016-08-‌23 08:08:40","post_title":"wwwwAHHH"},{"pid":"223","date":"2016‌-08-23 08:08:40","post_title":"xxxAHHH"}]';

$objArray = json_decode($rows);

$newarray = array();
foreach($objArray as $v) 
{

    $v->newitem = 'Add this to existing object';
    $newarray[] = $v;
}
print_r($newarray);
echo json_encode($newarray);

$newArray现在是

Array
(
    [0] => stdClass Object
        (
            [pid] => 123
            [date] => 2016-08-23 08:08:40
            [post_title] => AHHH
            [newitem] => Add this to existing object
        )

    [1] => stdClass Object
        (
            [pid] => 223
            [date] => 2016-08-‌23 08:08:40
            [post_title] => wwwwAHHH
            [newitem] => Add this to existing object
        )

    [2] => stdClass Object
        (
            [pid] => 223
            [date] => 2016‌-08-23 08:08:40
            [post_title] => xxxAHHH
            [newitem] => Add this to existing object
        )

)

新的JSON字符串将是

[  {"pid":"123",
    "date":"2016-08-23 08:08:40",
    "post_title":"AHHH",
    "newitem":"Add this to existing object"
   },
   {"pid":"223",
    "date":"2016-08-\u200c\u200b23 08:08:40",
    "post_title":"wwwwAHHH",
    "newitem":"Add this to existing object"
   },
   {"pid":"223",
    "date":"2016\u200c\u200b-08-23 08:08:40",
    "post_title":"xxxAHHH",
    "newitem":"Add this to existing object"
   }
]

Answer 2

在场景1中，每次都为同一个数组键分配一个不同的值$ v，因此它被覆盖（并最终成为传递给foreach的最后一行的值）： / p>

$newarray['newitem'] = 'Add this to existing object';

场景2位于正确的位置，但需要稍微改变。在场景2中，您将添加一个包含$ v的数组，但随后会立即覆盖它：

$newarray[$k] = $v;
$newarray[$k]['newitem'] = 'Add this to existing object';

您需要为项目提供单独的密钥，因此解决方案可能是使用“旧项目”。键将初始值分配给：

$newarray[$k]['olditem'] = $v;
$newarray[$k]['newitem'] = 'Add this to existing object';

您可以使用许多解决方案，具体取决于您希望如何构建阵列，但关键原则是确保值具有单独的键，以便它们不会相互覆盖。

如何在php中为数组内的每个对象添加一个新的键值对？

2 个答案: