到目前为止这些变化为何没有生效？

Question

我有这个代码应该改变输出的日期，但我没有得到任何改变。任何人都可以看到有什么问题吗？

<?php 
$tempStartDate = "2011-07-04 15:00:00";
$TempDaysFromEvent = "-14";

$newtempStartDate = explode(" ", $tempStartDate);
echo "New Temp Start Date: ".$newtempStartDate[0];
echo "<br>";
list($year, $month, $day) = explode("-", $newtempStartDate[0]);
echo $year." ". $month. " ". $day;
echo "<br>";

$tempStartDate  =  $tempEndDate  =  date("Y-m-d", mktime(0,0,0,$month,($day+$tempDaysFromEvent),$year));
echo "TempStart Date:".$tempStartDate."<br>";

?>

这给了我这个输出：

New Temp Start Date: 2011-07-04
2011 07 04
TempStart Date:2011-07-04

但我希望它能给我：

New Temp Start Date: 2011-07-04
2011 07 04
TempStart Date:2011-06-20

Answer 1

您应该收到此通知：

Notice: Undefined variable: tempDaysFromEvent in C:\tmp\test.php on line 12

您的变量实际上是$TempDaysFromEvent。 PHP中的变量区分大小写。

Answer 2

您定义$TempDaysFromEvent时有资金，因此请将其更改为

$tempStartDate  =  $tempEndDate  =  date("Y-m-d", mktime(0,0,0,$month,($day+$TempDaysFromEvent),$year));

Answer 3

你有错字

$tempDaysFromEvent代替$TempDaysFromEvent

Answer 4

一个不太复杂的解决方案：

$tempStartDate = "2011-07-04 15:00:00";
print date('Y-m-d H:i:s', strtotime('-14 days', strtotime($tempStartDate)));