我正在为我儿子写的剧本有问题.我的意图是提醒他记住他的家务.我刚刚开始做Power
Shell,我真的非常喜欢它.我已经买了几本书,还经历了很多其他的帖子.
到目前为止我所得到的是,似乎评估与-or无法正常工作(或者我可能会这么做？)
## REMINDERS TO DO CHORES ##
$sun = "Sunday"
$mon = "Monday"
$tue = "Tuesday"
$wed = "Wednesday"
$thu = "Thursday"
$fri = "Friday"
$sat = "Saturday"
$today = (get-date).DayOfWeek
$choreVac = "Vacuum the rooms and stairs"
$choreBath = "Clean the Bathroom Including emptying the garbage"
$choreOther = "No Chores Today -- But keep dishes done up"
if($today -eq $mon -or $wed -or $fri) {
msg /time:2500 * "Today is a Chore Day: your job is to $choreVac"
}
elseif ($today -eq $tue -or $sat ) {
msg /time:2500 * "Today is a Chore Day: your job is to $choreBath and PLEASE do a good job"
}
else {
msg /time:2500 * $choreOther
}
问题是我不认为它在当天被正确评估,所以今天是星期二,评估结果是$mon -or $wed -or $fri
如果我按照以下方式对每天进行重新编码,那就像预期的那样工作.为什么不使用-or？
if($today -eq $tue) {
msg /time:2500 * $choreBath
}
解决方法
就像你发现自己一样,PowerShell没有评估你的if语句你的预期.你的表达可以更好地理解为：
if(($today -eq $mon) -or ($wed) -or ($fri))
$today -eq $mon -or $today -eq $wed -or $today -eq $fri
或另一种看待它的方式.
($today -eq $mon) -or ($today -eq $wed) -or ($today -eq $fri)
PowerShell不需要括号,但如果事情不顺利,最好使用它们.
当转换为布尔值时,PowerShell中的非null /零长度字符串为true.专注于第二个条款,它可以改写为
"Wednesday" -or "Friday"
这总是如此.这就是为什么你的if语句在你不期望的时候被触发的原因.
你编码的内容有一定的逻辑意义,但它在语法上是不正确的.我想向你介绍的另一种方法,如果你还不熟悉它,那就是switch.它将有助于减少所有if语句的混乱,如果随着时间的推移它们变得越来越复杂,它们将特别有用.
$today = (get-date).DayOfWeek
$choreVac = "Vacuum The Apt"
$choreBath = "Clean the Bathroom Including empting the garbage"
$choreOther = "NO CHORES TODAY -- BUT YOU CAN Keep dishes done up,and Keep Garbage from Overflowing AND CLEAN YOUR ROOM and OR Do Laundry!!!. Especially your bedding"
Switch ($today){
{$_ -in 1,3,5}{$message = "Today is a Chore Day: Your job is to`r$choreVac"}
{$_ -in 2,6}{$message = "Today is a Chore Day: Your job is to`r$choreBath and PLEASE do a good job"}
default{$message = $choreOther}
}
msg /time:2500 * $message
我们将所有对msg的调用删除为一个语句,因为只有$message更改.如果一个苦差日没有被交换机中的条款覆盖,那么默认值只是$choreOther.
一周中的日子也可以表示为整数,就像你在上面看到的那样.这可能会降低代码的可读性,但我认为这是一个延伸.
