PowerShell Cheat Sheet (2) - Conditions, Loops, Script Blocks

# If/then
if ($x -eq 1)
{
}
else
{
}
#Switch
$x = 1
switch($x)
{
  1 {"One"}
  "1" {"One - string"}
  2 {"Two"; break}
  default {"Default"}
}
switch -casesensitive ("Lukasz")
{
  "lukasz" {"lysik"}
  "Lukasz" {"Lysik"}
}
switch -Wildcard ("Lukasz")
{
  "L*" {"Lysik"}
}

# While
while($x -le 1)
{
}

# Do while
do {
} while($x -le 1)

# Do until
do {
} until($x -eq 1)

# For
for($x=0; $x -lt 10; $x++)
{
}

# Foreach
$numbers = 10,20,30,40
foreach($n in $numbers)
{
}

# Labels with loops
:level1 foreach(...)
{
  foreach(...)
  {
    break level1
    # continuer outerloop
  }
}

# Assign to variable
$script = {Clear-Host; "Hello World!"}

# Executing
& $script

# Executing script block
& {"Hello World!"}

# Passing parametes to script blocks
$script = {
  $x = $args[0]
  $y = $args[1]
}

# Executing with parameters
& $script 1 2

# Passing parametes to script blocks (alternative)
$script = {
  param($x,$y)
}

# Executing
& $script -x 1 -y 2
# Default values
$script = {
  param($x, $y = 1)
}

# Using script block with pipelines
$script = {
  begin { Write-Host "Start" }
  process {
    Write-Host $_
  }
  end { Write-Host "End" }
}