Powershell Data Types

The most common DataTypes used in PowerShell are listed below

 [string]    Fixed-length string of Unicode characters
 [char]      A Unicode 16-bit character
 [byte]      An 8-bit unsigned character

 [int]       32-bit signed integer
 [long]      64-bit signed integer
 [bool]      Boolean True/False value

 [decimal]   A 128-bit decimal value
 [single]    Single-precision 32-bit floating point number
 [double]    Double-precision 64-bit floating point number
 [DateTime]  Date and Time

 [xml]       Xml object
 [array]     An array of values
 [hashtable] Hashtable object

Powershell has two built in variables $true and $false for displaying the true and false boolean values.
There is also [void] casting an expression to the void datatype will effectively discard it (like redirecting to $null)

To force a conversion to a specific datatype, prefix the value or variable with the type in square brackets, this is known as a Cast Operator and forces the chosen datatype:

PS C:\> [int]"0064"
PS C:\> [int]$false

When reading in data supplied by a user (with read-host) casting to [string] will return a String even if the user enters 123

If you cast a fractional value to an integer, PowerShell will Round() the result, to strip off all decimals behind the decimal point, use Truncate() from the .NET Math library.

Casting a string into [DateTime]will by default accept USA format dates MM/DD/YYYY or ISO 8601 YYYY-MM-DD. You can override this by using ::ParseExact to specify the exact format of the date string you are supplying.

For example to cast a date string "08-12-2012" that’s in UK format:
PS C:\> [DateTime]::ParseExact("08-12-2012","dd-MM-yyyy",[System.Globalization.CultureInfo]::InvariantCulture)
Saturday, December 08, 2012 00:00:00

Cast a date string "09-Jun-2012" that’s in UK format and then display it as "yyyy-MM-dd"
PS C:\> [DateTime]::ParseExact("09-Jun-2012","dd-MMM-yyyy",[System.Globalization.CultureInfo]::InvariantCulture).ToString("yyyy-MM-dd")
2012-06-09

To test the datatype of a value use a comparison operator:

PS C:\> 32 -is [int]            -> true
PS C:\> $true -is [bool]        -> true

In addition to the above, if you are using other .NET classes then you can use those DataTypes too.

“Character is what we do when no one's looking” ~ Bill Hybels

Related:

Variables and Operators - Create, add, subtract, divide.
DateTime formats
Get-Item Variable:
Get-Variable