Variables in strings

In PowerShell, variables can be included within any double-quoted string. The value of that variable will expand when the string is created.

For example:

$count = 5
$string = "There are $count items"

Variables will not expand inside single-quoted or literal strings.

Provider-specific values will also expand inside a double-quoted string:

"Computer Name: $env:COMPUTERNAME"

The example above uses a colon to split the provider name, env, from the variable name, COMPUTERNAME. If a colon is present after a variable name, PowerShell will always interpret it as a provider name.

In the following example, the first variable in the string ends with a colon, which causes a parser error:

PS> $computerName = $env:COMPUTERNAME
PS> "$ComputerName: Running PS $PSEdition"
ParserError:
Line |
   1 |  "$ComputerName: Running PS $PSEdition"
     |   ~~~~~~~~~~~~~~
     | Variable reference is not valid...