01-Fundamentals

Installing Powershell 7
https://learn.microsoft.com/en-us/powershell/scripting/install/install-powershell-on-windows?view=powershell-7.5

• Warning: the profile location of PS5 and PS7 is difference

Powershell use objects for input/output

Get-Member

• get object properties of an object passed into it

Get-Alias
Get-Command

• check command or alias

Variables

$variable="string"

Similar to Python, Powershell variables are like classes and it has attributes and methods

$variables.GetType()

• get the type of variable similar to type()

Nulls are object without type or assigned value

• cannot be used with Get-Member or GetType()

Use [] to force a type

[int]$myvalue=1.23

• force $myvalue to an integer, so it will be 1
• when using int, it will round the number
• [] is a useful function as parseInt

Powershell is weakly typed, when concat different types, the second value will be coerced into the type of the first

• except for int, where it will be treated as double even when adding string

1 + "1" # 2
"1" + 1 # 11
"1.1" + 1.1 # 1.11.1
1.1 + "1.1" # 2.2

Strings

String has the attribute

• length

String can be converted into array and be iterated over

$mystr.ToCharArray()

Integer

[int]1
([int]1/2)

• it’s useful to add () around the integer since 1/2 will result in 0.5 and will be a double

Boolean

$true $false

• these are automatic read-only variables and cannot be used as variable names
• $false and $null are not the same

Other

Take a user input

$inp = Read-Host -Prompt ""

Timeout for seconds

Sleep 5

Benchmark functions

Measure-Command { action }