未定义变量：$sameday at somthing.php

我将在something.php上为特色活动编写此代码

$day_start = date("j", mktime(0,0,0,$event_start_month, $event_start_day, $event_start_year));

$day_end = date("j", mktime(0,0,0, $event_end_month, $event_end_day, $event_end_year));



        if (($day_start == $day_end)) {
            $same_day = true;
        }
        <?php if ($same_day == false) { ?>
<span class="value value-date"> - <?php echo $day_end; ?></span>

---

您应该始终为

$same\u day

分配一些内容，以避免出现此警告。像这样：

if (($day_start == $day_end)) {
        $same_day = true;
    } else{
        $same_day =false; // <-- This is the new part.
    }
...
if ($same_day == false) {

if（$day\u start==$day\u end））{
$same_day=正确；
}否则{
$same_day=false；//使用此选项可避免错误

$same_day = false;

if (($day_start == $day_end)) {
        $same_day = true;
    } 

......

 <?php if ($same_day == false) { ?>
            <?php echo $day_end; ?>

$same\u day=false；
如果（$day\u start==$day\u end））{
$same_day=正确；
} 
......

if (($day_start == $day_end)) {
        $same_day = true;
    } else{
        $same_day =false; // <-- This is the new part.
    }
...
if ($same_day == false) {

$same_day = false;

if (($day_start == $day_end)) {
        $same_day = true;
    } 

......

 <?php if ($same_day == false) { ?>
            <?php echo $day_end; ?>