PowerShell Data Types

Every value in PowerShell is a .NET object, which means every variable carries an underlying data type that defines what operations can be performed on it. PowerShell can infer types automatically, but understanding the common types is essential for writing predictable scripts, handle numeric precision properly, and build structured custom data models.

Core Data Types

PowerShell maps standard programming types to .NET classes using convenient bracketed shortcuts called type accelerators (e.g., [string], [int]).

String

A string represents text data, enclosed in single or double quotes.

$name = "PowerShell"
$name.GetType().Name

String

Char

A char stores a single Unicode character, declared using the [char] type accelerator.

[char]$grade = "A"
$grade.GetType().Name

Char

Int (Integer)

An integer stores whole numbers without a decimal point.

$count = 42
$count.GetType().Name

Int32

Long (64-bit Integer)

A long is a 64-bit signed integer, represented by the .NET System.Int64 type. It is useful when an integer value may exceed the range supported by [int].

The [long] and [int64] type accelerators refer to the same underlying .NET type.

$count = [long]922337203685477580
$count.GetType().Name

Int64

A 32-bit [int] can store values from -2,147,483,648 through 2,147,483,647, while [long] supports the much larger range from -9,223,372,036,854,775,808 through 9,223,372,036,854,775,807.

You can explicitly declare a variable as a [long]:

[long]$fileSize = 5000000000
$fileSize.GetType().Name

Int64

Double

A double stores floating-point (decimal) numbers.

$price = 19.99
$price.GetType().Name

Double

Boolean

A boolean stores one of two values: $true or $false.

$isEnabled = $true
$isEnabled.GetType().Name

Boolean

Array

An array is an ordered collection of values, declared using the @() subexpression syntax.

$colors = @("Red", "Green", "Blue")
$colors.GetType().Name

Object[]

Hashtable

A hashtable stores data as unordered key-value pairs, declared using @{}.

$user = @{ Name = "Tom"; Age = 30 }
$user.GetType().Name

Hashtable

DateTime

A DateTime object represents a specific point in time, typically created with Get-Date.

$today = Get-Date
$today.GetType().Name

DateTime

Value Types vs Reference Types

Under the hood, every .NET type used by PowerShell falls into one of two categories: value types or reference types. This distinction affects how variables behave when copied or passed around.

$a = 5
$b = $a
$b = 10
Write-Output "a=$a b=$b"

$arr1 = @(1, 2, 3)
$arr2 = $arr1
$arr2[0] = 99
Write-Output "arr1=$arr1"

where:

• $b = $a copies the integer value, so changing $b has no effect on $a.
• $arr2 = $arr1 copies the reference to the same underlying array, so modifying $arr2 also changes $arr1.

./value-vs-reference.ps1

a=5 b=10
arr1=99 2 3

Numeric Literal Suffixes

PowerShell supports special suffixes on numeric literals to control their type or scale without needing an explicit cast.

$fileLimit = 5mb
Write-Output $fileLimit

5242880

The GetType() Method

Every object in PowerShell inherits a .GetType() method, which returns detailed type information, including the full .NET namespace and base type.

(5).GetType() | Format-List

IsPublic     : True
IsSerial     : True
Name         : Int32
BaseType     : System.ValueType

where:

• Name shows the short type name (Int32).
• BaseType shows the parent .NET class the type derives from.

Type Casting and Conversion

PowerShell allows explicit type casting using square bracket type accelerators, converting a value from one type to another.

$strNumber = "100"
[int]$intNumber = $strNumber
$total = $intNumber + 50
Write-Output $total

where:

• [int]$intNumber = $strNumber explicitly converts the string "100" into an integer.
• Without the cast, adding a string and a number can produce unexpected string concatenation instead of arithmetic.

./type-casting.ps1

150

You can also use the .NET conversion methods or the -as operator for safer, non-throwing conversions:

$value = "42" -as [int]
$value.GetType().Name

Int32

Introduction to [PSCustomObject]

A [PSCustomObject] is a lightweight, structured object type used to group related properties together, similar to a "record" or "struct" in other languages. It's the preferred way to build custom data structures in PowerShell.

$employee = [PSCustomObject]@{
    Name       = "Jamie"
    Department = "IT"
    HireDate   = Get-Date "2026-01-10"
}

$employee

where:

• [PSCustomObject]@{ ... } converts a hashtable literal into a structured, ordered object.
• Each key becomes a named property accessible via dot notation ($employee.Name).

./custom-object.ps1

Name  Department HireDate
----  ---------- --------
Jamie IT         1/10/2026 12:00:00 AM