How does $(......) work?

Question

Hello,
Can someone plz explain and provide references to how $(....) works below and why we use it.
$mycred = Get-Credential
$CompName = Read-Host -Prompt "Enter Computer Name"
Write-Debug "user name: $($mycred.UserName)"
Write-Debug "password: $($mycred.GetNetworkCredential().Password)"
Thanks for your help! SdeDot

Answer 1

$() is the subexpression operator. It's used primarily when you want to expand a full expression inside of a double quoted string, instead of simply expanding a variable to its string representation.
For example, "$mycred.UserName" would return a string of "<something>.UserName", where <something> is whatever the result of [string]$mycred would be, and ".UserName" was treated as literal text.  By using the subexpression operator, you'd
be telling PowerShell to evaluate the result of $myCred.UserName (as if it were typed in a command of its own), and put the resulting value into the string:  "$($mycred.UserName)".
See the about_Quoting_Rules help file for all the details on this.