PHP在for循环中向数组添加新值答案

【问题标题】：PHP adding new values to an array in for loopPHP在for循环中向数组添加新值
【发布时间】：2015-04-07 19:10:06
【问题描述】：

请有人告诉我我在代码中犯的错误，如下所示：

$arrayOfDays = array();
    for($dayIterator=$from; $dayIterator < $to; $dayIterator->modify('+1 day')){
        $arrayOfDays[] = $dayIterator;
    }
    print_r($arrayOfDays);

打印出这样的结果：

Array ( [0] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [1] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [2] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [3] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [4] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [5] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [6] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [7] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [8] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [9] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [10] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [11] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [12] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [13] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [14] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [15] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [16] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [17] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [18] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [19] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [20] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [21] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [22] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [23] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [24] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [25] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [26] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [27] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) [28] => DateTime Object ( [date] => 2015-04-30 00:00:00 [timezone_type] => 3 [timezone] => Europe/Paris ) )

其中 $from 设置为月初，$to 设置为月底。当我在循环中打印 $dayIterator 时，它给了我正确的日期，但是在完成整个数组后，最后一天就被填满了！！我不知道为什么它会这样工作:(

【问题讨论】：

$from 和 $to 值是什么样的？
只是提示：PHP 对象是通过引用传递的。所以你保存对对象的引用 30 次；）你可以通过保存一个克隆来解决它

标签： php arrays loops while-loop

【解决方案1】：

也许你可以尝试不同的方法，比如DatePeriod

你必须提供的是：

开始/结束 DateTime 对象和 DateInterval 对象。

快速示例：

<?php
$range = new DatePeriod(
    new DateTime('2015-01-01'),
    new DateInterval('P1D'),
    new DateTime('2015-01-31 23:59:59')
);

foreach($range as $dateTime) {
    print $dateTime->format('d M Y') . '<br>';
}

DateInterval 中的

P1D 表示 - Period 1 Day

23:59:59 在第二个日期时间对象中的原因是，如果你想在你的日期范围中包含你的最后一个日期，你必须至少为你的对象添加 1 秒。

希望你明白了。

【讨论】：

【解决方案2】：

这是因为您使用的是同一个对象，而不是实例化一个新对象。

只需在每次迭代中调用一个新实例：

$dayIterator = new DateTime(/* --- */);

【讨论】：