如何在一个数组中使用foreach来计算小于10的数字？

Question

我想在PowerShell中计算一个数组中小于10的数字，我必须使用foreach循环。

cls 
$a = 0..9
$i = 0

foreach ($element in $a) {
  if ($element -gt 2)
  {
   $i = $i + 1
   Write-Host $i
  }
}

Answer 1

更改 -gt ("大于")至 -lt ("小于")，并改变 2 到 10:

foreach ($element in $a) {
  if ($element -lt 10)
  {
    $i = $i + 1
  }
}
Write-Host "Counted $i numbers under 10"

Answer 2

这里有另一种获得计数的方法。它过滤出不小于限制的项目，将它们发送到另一个$Var，然后使用 .Count 最后，它显示了小于极限值的数字列表。

代码& 注释似乎很清楚，但如果你有问题，请问...[。咧嘴一笑]

# only the last 3 items are NOT less than 10
$NumberList = @(1,3,5,7,9,1,1,4,0,-1,-666,111,666,10)
$Limit = 10

$TotalNumbers = $NumberList.Count
# a ".Where()" method call would be more obvious
#    so would piping to `Where-Object`
#    however, the requirement is to use a "foreach" loop [*grin*] 
$LessThanLimit = foreach ($NL_Item in $NumberList)
    {
    if ($NL_Item -lt $Limit)
        {
        $NL_Item
        }
    }

'Total Numbers             = {0}' -f $NumberList.Count
'Numbers less than [ {0,3} ] = {1}' -f $Limit, $LessThanLimit.Count
"$LessThanLimit"

产量...

Total Numbers             = 14
Numbers less than [  10 ] = 11
1 3 5 7 9 1 1 4 0 -1 -666