演算子

PS> 2 -eq 2
True
PS> 1 -eq 2
False
PS> 1,2,3 -eq 2
2

PS> 2 -ne 2
False
PS> 1 -ne 2
True
PS> 1,2,3 -ne 2
1
3

PS> 1 -gt 1
False
PS> 2 -gt 1
True
PS> 1,2,3 -gt 1
2
3

PS> 1 -ge 1
True
PS> 2 -ge 1
True
PS> 1,2,3 -ge 1
1
2
3

PS> 1 -lt 1
False
PS> 1 -lt 2
True
PS> 1,2,3 -lt 2
1

PS> 1 -le 1
True
PS> 1 -le 2
True
PS> 1,2,3 -le 2
1
2

PS> 1,2,3 -contains 2
True
PS> 1,2,3 -contains 4
False

PS> 1,2,3 -notcontains 2
False
PS> 1,2,3 -notcontains 4
True

PS> 2 -in 1..10
True

PS> 2 -notin 1..10
False

PS> 'abc' -is [String]
True
PS> 'abc' -is [Int]   
False
PS> 'abc'.GetType()   

IsPublic IsSerial Name                                     BaseType
-------- -------- ----                                     --------
True     True     String                                   System.Object

PS> 'abc' -isnot [String]
False
PS> 'abc' -isnot [Int]   
True

PS> "PowerShell" -ceq "powershell"
False

PS> "PowerShell" -eq "powershell" 
True

PS> "PowerShell" -ieq "powershell"
True

PS> "PowerShell" -like "*shell" 
True

PS> "PowerShell" -notlike "*shell"
False

PS> "PowerShell", "ShellPower" -match "^power" 
PowerShell

PS> 1234 -match '(.)(.)(.)(.)'
True
PS> $Matches

Name                           Value
----                           -----
4                              4
3                              3
2                              2
1                              1
0                              1234

PS> 'strings user=powershell, id=100 strings' -match '(?:user=)(?<user>\w+), (?:id=)(?<id>\d+)'      
True
PS> $Matches

Name                           Value
----                           -----
id                             100
user                           powershell
0                              user=powershell, id=100

# userとidを取得できている！
PS> $Matches.user
powershell
PS> $Matches.id
100
PS>

PS> "PowerShell", "ShellPower" -notmatch "^power"
ShellPower

PS> "PowerShell" -replace "Shell", "Point"
PowerPoint

# 拡張子変換の例
PS> Get-ChildItem *.txt | Rename-Item -NewName { $_.name -replace '\.txt$','.log' }

PS> 'PowerShell' -replace '(Power)(Shell)', '$2$1'
ShellPower

PS> 'PowerShell' -replace '(?<power>Power)(?<shell>Shell)', '${shell}${power}'
ShellPower

PS> -split "Power Shell"
Power
Shell
PS> "Power,Shell" -split ","
Power
Shell

# 失敗例
PS> -join "a", "b", "c"
a
b
c

# 成功例
PS> -join ("a", "b", "c")
abc

PS> "a", "b", "c" -join ""                
abc

# 指定した文字列を使って、文字列を結合する
PS> "Power", "Shell" -join ","
Power,Shell

PS> "{0}{1}" -f "Power", "Shell"       
PowerShell

# Dec => Hex
PS> '0x{0:x}' -f 255             
0xff
PS> '0x{0:X}' -f 255             
0xFF

# Display with zero
PS> '{0:d8}' -f 255
00000255

# Padding. 左詰め・右詰め
PS> '|{0,-8}|' -f 255
|255     |
PS> '|{0,8}|' -f 255 
|     255|

# PadLeftメソッドの使用例
PS> (255).ToString().PadLeft(8)    
     255
PS> (255).ToString().PadLeft(8," ")
     255
PS> (255).ToString().PadLeft(8,"0")        
00000255

PS> (1 -eq 1) -and (1 -eq 2)
False

PS> (1 -eq 1) -or (1 -eq 2)
True

PS> (1 -eq 1) -xor (2 -eq 2)
False

PS> -not (1 -eq 1)
False

PS> !(1 -eq 1)
False

PS> $command = "Get-Date"     
PS> $command                  
Get-Date
PS> & $command                

2020年11月25日 水曜日 16:26:11

PS> {Get-Date}
Get-Date
PS> & {Get-Date}

2020年11月25日 水曜日 16:29:48

PS> Get-Content ./script.ps1
Get-Date
PS> & ./script.ps1

2020年11月25日 水曜日 16:31:38

PS> 1..3    
1
2
3
PS> 1..-1
1
0
-1
PS> 'a'..'c'
a
b
c
PS> 'A'..'C'
A
B
C

# 構文
<condition> ? <if-true> : <if-false>

# 三項演算子を使用して、Yearが'Odd'か'Even'を出力する例
PS> (Get-Date).ToString("yyyy") % 2 ? 'Odd' : 'Even'
Even

PS> Write-Output 'Success' && Write-Error 'Error'
Success
Write-Error: Error

PS> Write-Error 'Error' && Write-Output 'Success'
Write-Error: Error

PS> Write-Output 'Success' || Write-Error 'Error'
Success
PS> Write-Error 'Error' || Write-Output 'Success'
Write-Error: Error
Success

# $num is $null
PS> $num
PS> $num ?? 100
100

# $num is not $null
PS> $num = 1
PS> $num ?? 100
1

# $num is $null
PS> $num = $null
PS> $num ??= 100
PS> $num
100

# $num is not $null
PS> $num = 1
PS> $num ??= 100
PS> $num
1