PHP 在 for 循环中向数组添加新值

Question

你能告诉我我在我的代码中犯的错误吗，它看起来是这样的：

$arrayOfDays = array();
    for($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 设置为月末。当我在循环中打印 $dayIterator 时，它给了我正确的日期，但完成后整个数组都填满了最后一天！！我不知道为什么它会那样工作:(

Answer 1

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。

每次迭代只调用一个新实例：

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

Answer 2

也许你可以尝试不同的方法，比如 DatePeriod

您需要提供的是：

Start/End 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>';
}

P1D 在 DateInterval 中表示 - Period 1 Day

第二个日期时间对象中 23:59:59 的原因是，如果您想在日期范围内包含最后一个日期，则必须至少添加 1 秒给你的对象。

希望你明白了。

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