foreach 循环中的最后一项是它正在遍历的数组答案

【问题标题】：Last item in foreach loop is the array it is traversingforeach 循环中的最后一项是它正在遍历的数组
【发布时间】：2014-08-19 04:30:17
【问题描述】：

我有一组包含日期、开始时间和结束时间的本周、下周和下周的日期。出于某种原因，当 foreach 循环到达最终日期时，它会输出最后一周的数组而不是最终日期。这是数组的开头：

$dates = Array
(
    [0] => Array
        (
            [0] => Array
                (
                    [0] => "Mon 23rd June"
                    [1] => "9:00am"
                    [2] => "7:00pm"
                )

            [1] => Array
                (
                    [0] => "Tue 24th June"
                    [1] => "9:00am"
                    [2] => "7:00pm"
                )
            ...
    [1] => Array
        (

            [0] => Array
                (
                    [0] => "Mon 30th June"
                    [1] => "9:00am"
                    [2] => "7:00pm"
                )

            [1] => Array
                (
                    [0] => "Tue 1st July"
                    [1] => "9:00am"
                    [2] => "7:00pm"
                )
            ...

数组没有问题，因为我已经打印出来了。这是foreach循环（它是发生错误的嵌套foreach（$week as $day））：

foreach($dates as $week)
{ 
    if($i == 2)
    {
        $html .= '<table cellpadding="5" cellspacing="2" border="0" class="kc_ot_openingTable last">';
    }
    else
    {
        $html .= '<table cellpadding="5" cellspacing="2" border="0" class="kc_ot_openingTable">';
    }
    $html.= '<tr class="kc_ot_weekCommence">
        <td colspan="3">Week Commencing '.$week[0][0].'</td>
    </tr>
    <tr class="kc_ot_openingTableTitle">
        <td class="day">Day</td>
        <td class="open">Open</td>
        <td class="closed">Closed</td>
    </tr>';

    foreach($week as $day)
    {
        $html .= '<tr>
        <td>'.$day[0].'</td>
        <td class="open">'.$day[1].'</td>
        <td class="closed">'.$day[2].'</td>
    </tr>
    <tr>';
    }
    $html .= '</table>';
    ++$i;
}

谁能看出发生了什么？

编辑

我发现 $dates 没问题，问题是在上周运行 foreach($dates as $week) 循环时出现的。

重新编辑

这是 this 来自的函数。请不要判断，我继承了这个网站：P

function getOpeningHours() {

date_default_timezone_set('Europe/London');
$dates = array(
    array(
        array(
            date("D jS F", strtotime("monday this week")),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("tuesday this week")),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("wednesday this week")),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("thursday this week")),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("friday this week")),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("saturday this week")),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("sunday this week")),
            "9:00am",
            "7:00pm"
        ),
    ),
    array(
        array(
            date("D jS F", strtotime("monday next week")),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("tuesday next week")),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("wednesday next week")),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("thursday next week")),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("friday next week")),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("saturday next week")),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("sunday next week")),
            "9:00am",
            "7:00pm"
        ),
    ),
    array(
        array(
            date("D jS F", strtotime("monday next week", strtotime("monday next week"))),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("tuesday next week", strtotime("tuesday next week"))),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("wednesday next week", strtotime("wednesday next week"))),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("thursday next week", strtotime("thursday next week"))),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("friday next week", strtotime("friday next week"))),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("saturday next week", strtotime("saturday next week"))),
            "9:00am",
            "7:00pm"
        ),
        array(
            date("D jS F", strtotime("sunday this week", strtotime("sunday next week"))),
            "9:00am",
            "7:00pm"
        )
    ),
);

$sql[0] = "SELECT * FROM `tbl_opening_exceptions` WHERE `exception_date`  >= '".date("Y-m-d", strtotime("monday this week"))."' AND `exception_date` <= '".date("Y-m-d", strtotime("sunday this week"))."'";
$sql[1] = "SELECT * FROM `tbl_opening_exceptions` WHERE `exception_date`  >= '".date("Y-m-d", strtotime("monday next week"))."' AND `exception_date` <= '".date("Y-m-d", strtotime("sunday next week"))."'";
$sql[2] = "SELECT * FROM `tbl_opening_exceptions` WHERE `exception_date`  >= '".date("Y-m-d", strtotime("monday next week", strtotime("monday next week")))."' AND `exception_date` <= '".date("Y-m-d", strtotime("sunday next week", strtotime("sunday next week")))."'";
$i=0;
foreach($sql as $string)
{
    $result = mysql_query($string) or die(mysql_error());
    $r = mysql_fetch_array($result);

    foreach($dates[$i] as &$week)
    {
        if($week[0] == date("D jS F", strtotime($r["exception_date"])))
        {
            $week[1] =  date("g:ia", strtotime($r["exception_opening"]));
            $week[2] = date("g:ia", strtotime($r["exception_closing"]));
        }
    }
    ++$i;
}
$html = "";
$i = 0;
//print_r($dates);
foreach($dates as $week)
{ 
print_r($week);
    if($i == 2)
    {
        $html .= '<table cellpadding="5" cellspacing="2" border="0" class="kc_ot_openingTable last">';
    }
    else
    {
        $html .= '<table cellpadding="5" cellspacing="2" border="0" class="kc_ot_openingTable">';
    }
    $html.= '<tr class="kc_ot_weekCommence">
        <td colspan="3">Week Commencing '.$week[0][0].'</td>
    </tr>
    <tr class="kc_ot_openingTableTitle">
        <td class="day">Day</td>
        <td class="open">Open</td>
        <td class="closed">Closed</td>
    </tr>';

    foreach($week as $day)
    {
        $html .= '<tr>
        <td>'.$day[0].'</td>
        <td class="open">'.$day[1].'</td>
        <td class="closed">'.$day[2].'</td>
        </tr>';
    }
    $html .= '</table>';
    ++$i;
}
return $html;
}

【问题讨论】：

您在内部foreach 的HTML 末尾有一个额外的<tr>。
澄清一下，3 个表格中的每一个都将最后一行打印两次？还是只是最后一张桌子？
$dates[2][6] 中的最后一个星期日包含 $dates[2] 数组，当我查看它的 print_r() 时，它会显示 recursion。输入到 foreach($dates as $week) 的数组很好，当 foreach 运行时会发生错误。
不影响报错。所以卡住了！
@PhilYoung 找到了，邪恶的引用:)

标签： php arrays foreach output

【解决方案1】：

TL;DR - 引用是邪恶的！

问题出在这里：

foreach ($dates[$i] as &$week) {
    // updates based on database values
}

foreach ($dates as $week) {
    // generate html from week data
}

第一个循环结束后，上周仍然是一个参考，$dates[count($dates) - 1] 也是如此。在第二个循环中，$week 被依次分配给$dates 的每个元素。

当涉及到最后一个元素时，$week 被分配给它自己，从而创建了一个递归结构。

修复很简单：

foreach ($dates[$i] as &$week) {
    // updates based on database values
}
unset($week); // remove the reference

或者：

foreach ($dates[$i] as $week) {
    // updates based on database values
    if (<some condition>) {
        $dates[$i][1] = 'foo';
        $dates[$i][2] = 'bar';
    }
}

【讨论】：

这么简单的事情，我已经花了很长时间试图对它进行排序！谢谢:)
@PhilYoung 不客气；假设你在英国，你现在一定很累了:)
是的，我是，凌晨 3 点 10 分！这个迟到的编码会议不应该运行这么长时间！哈哈。

【解决方案2】：

好的，

$weeks = array(
array(
array("Mon 23rd June", "9:00 AM", "7:00 PM"),
array("Tue 24th June", "9:00 AM", "7:00 PM"),
array("Wed 25th June", "9:00 AM", "7:00 PM") //etc
),
array() // another week 
)
$dates = array($weeks)

因此，如果您的目标只是打印“6 月 23 日星期一”，请尝试

print_r(day[0][0]);

另外，下次再提一下你是如何声明数组的，这会变得容易得多。我认为您的 $weeks 数组从外观上应该称为 $week 。

也似乎是无意的

编辑：我发现了错误

array(
        date("D jS F", strtotime("monday next week", strtotime("monday next week"))),
        "9:00am",
        "7:00pm"
    ),

执行类似 date("D jS F", strtotime("monday next week + 7 day")。这将得到下周星期一 +7 天，也就是两周后的星期一。我不认为“”下周星期一”，strtotime(“下周星期一”)”是有效的语法。同样的错误可能在这里：

$sql[2] = "SELECT * FROM `tbl_opening_exceptions` WHERE `exception_date`  >= '".date("Y-m-d", strtotime("monday next week", strtotime("monday next week")))."' AND `exception_date` <= '".date("Y-m-d", strtotime("sunday next week", strtotime("sunday next week")))."'";

只是建议更好地生成日期，但对于您的商店或任何可能最方便的方式。 Create an array/collection/list of (Date,Value) in PHP 使用它来创建你的数组，如果你必须将它分成几个星期使用 array_chunk[$dates, 7]

重新编辑：

查看日期数组的末尾

  array(
        date("D jS F", strtotime("saturday next week", strtotime("saturday next week"))),
        "9:00am",
        "7:00pm"
    ),
    array(
        date("D jS F", strtotime("**sunday *this* week**", strtotime("sunday next week"))),
        "9:00am",
        "7:00pm"
    )

将其更改为下周 + 7 天，我认为它可能会有所帮助。

【讨论】：

抱歉，print_r 只是我在调试。除了最后一天，我所有的日子都在工作：/
这样更有意义：将 foreach($week as $day) 更改为 foreach($day as $dayInfo) ，然后我认为您可以将 $weeks 更改为 $week 和 $dates 更改为 $weeks 在最顶部跨度>
$weeks 在哪里？我有 $dates，它是一个包含 3 个 $weeks 的数组，而它又是一个包含 7 个 $days 的数组。
我以为它在顶部，但它在那里是 $week。从头开始，它应该类似于 foreach ($weeks as $week) { foreach ($week as day) 然后 foreach ($day as $dayinfo)。至少你是如何描述数组的，它是一个有 4 周的数组（$weeks 有 4 个 $week 数组），每周有 7 个 $day 数组（$week 有 7 个 $day），每个 $day 有一定的 $dayinfo。跨度>
和除此之外的清理，如果你把它变成一个函数，你可以在 $weeks 数组中传递它，我会更能够使用它，因为我不太了解你的目标。用你给它输入的函数，你得到输出。你以一种程序化的方式进行设置，这种方式很糟糕，看起来很混乱。日期数组是如何创建的？也包括该代码