#定义变量
$a=10
$b=4
#计算变量
$result=$a*$b
$msg="保存文本"

#输出变量
$result
$msg

40
保存文本

PS C:\test> ${"I"like $}="mossfly"
PS C:\test> ${"I"like $}

PS C:\test> $item=Get-ChildItem .
PS C:\test> $item

  Directory: C:\test

Mode        LastWriteTime   Length Name
----        -------------   ------ ----
d----    2011/11/23   17:25      ABC
-a---    2011/11/24   18:30   67580 a.html
-a---    2011/11/24   20:04   26384 a.txt
-a---    2011/11/24   20:26   12060 alias
-a---    2011/11/24   20:27   12060 alias.ps1
-a---    2011/11/23   17:25     0 b.txt
-a---    2011/11/23   17:25     0 c.txt
-a---    2011/11/23   17:25     0 d.txt
-a---    2011/11/25   11:20    556 employee.xml
-a---    2011/11/24   17:37    7420 name.html
-a---    2011/11/28   15:30     63 ping.bat
-a---    2011/11/24   17:44   735892 Powershell_Cmdlets.html
-a---    2011/11/28   17:03     60 test.ps1
-a---    2011/11/23   17:37    242 test.txt
-a---    2011/11/28   16:42    170 test.vbs

PS C:\test> $result=3000*(1/12+0.0075)
PS C:\test> $result
272.5

PS C:\test> $a=$b=$c=123
PS C:\test> $a
123
PS C:\test> $b
123
PS C:\test> $c
123

$Value1 = 10
$Value2 = 20
$Temp = $Value1
$Value1 = $Value2
$Value2 = $Temp

PS C:\test> $value1=10
PS C:\test> $value2=20
PS C:\test> $value1,$value2=$value2,$value1
PS C:\test> $value1
20
PS C:\test> $value2
10

PS C:\test> ls variable:

Name              Value
----              -----
"I"like $           mossfly
$               cls
?               True
^               cls
_
1               1
a               123
args              {}
b               123
c               123
ConfirmPreference       High
ConsoleFileName
DebugPreference        SilentlyContinue
。。。

PS C:\test> ls variable:value*

Name              Value
----              -----
value1             20
value2             10

PS C:\test> Test-Path variable:value1
True
PS C:\test> Test-Path variable:value2
True
PS C:\test> Test-Path variable:valueUnkonw
False

PS C:\test> Test-Path variable:value1
True
PS C:\test> del variable:value1
PS C:\test> Test-Path variable:value1
False

PS C:\test> New-Variable num -Value 100 -Force -Option readonly
PS C:\test> $num=101
Cannot overwrite variable num because it is read-only or constant.
At line:1 char:5
+ $num <<<< =101   + CategoryInfo     : WriteError: (num:String) [], SessionStateUnauthorizedAccessException   + FullyQualifiedErrorId : VariableNotWritable PS C:\test> del Variable:num
Remove-Item : Cannot remove variable num because it is constant or read-only. If the variable is read-only,
ration again specifying the Force option.
At line:1 char:4
+ del <<<< Variable:num
  + CategoryInfo     : WriteError: (num:String) [Remove-Item], SessionStateUnauthorizedAccessExcepti
  + FullyQualifiedErrorId : VariableNotRemovable,Microsoft.PowerShell.Commands.RemoveItemCommand

PS C:\test> del Variable:num -Force
PS C:\test> $num=101
PS C:\test> $num
101

PS C:\test> new-variable num -Value "strong" -Option constant

PS C:\test> $num="why? can not delete it."
Cannot overwrite variable num because it is read-only or constant.
At line:1 char:5
+ $num <<<< ="why? can not delete it."   + CategoryInfo     : WriteError: (num:String) [], SessionStateUnauthorizedAccessException   + FullyQualifiedErrorId : VariableNotWritable PS C:\test> del Variable:num -Force
Remove-Item : Cannot remove variable num because it is constant or read-only. If the variable is read-only,
ration again specifying the Force option.
At line:1 char:4
+ del <<<< Variable:num -Force
  + CategoryInfo     : WriteError: (num:String) [Remove-Item], SessionStateUnauthorizedAccessExcepti
  + FullyQualifiedErrorId : VariableNotRemovable,Microsoft.PowerShell.Commands.RemoveItemCommand

PS C:\test> new-variable name -Value "me" -Description "This is my name"
PS C:\test> ls Variable:name | fl *

PSPath    : Microsoft.PowerShell.CoreVariable::name
PSDrive    : Variable
PSProvider  : Microsoft.PowerShell.CoreVariable
PSIsContainer : False
Name     : name
Description  : This is my name
Value     : me
Visibility  : Public
Module    :
ModuleName  :
Options    : None
Attributes  : {}