how to handle $ inside parameters in powershell [duplicate] - sql-server

Question

The following code (at the bottom) produces one of the following outputs in the file
4/12/2019 = (get-date).AddDays(2).ToShortDateString();
4/13/2019 = (get-date).AddDays(2 + 1).ToShortDateString();
or if I haven't initialized the variable
= (get-date).AddDays(2).ToShortDateString();
= (get-date).AddDays(2 + 1).ToShortDateString();
This is the code block, I would like the parent ps1 file to write the child ps1 file verbatim.
$multiLineScript2 = #"
$startDate2 = (get-date).AddDays($resultOfSubtraction).ToShortDateString();
$endDate2 = (get-date).AddDays($resultOfSubtraction + 1).ToShortDateString();
"#
$multiLineScript2 | Out-File "c:\file2.ps1";

Answer 1

tl;dr:
To create a verbatim multi-line string (i.e., a string with literal contents), use a single-quoted here-string:
$multiLineScript2 = #'
$startDate2 = (get-date).AddDays($resultOfSubtraction).ToShortDateString();
$endDate2 = (get-date).AddDays($resultOfSubtraction + 1).ToShortDateString();
'#
Note the use of #' and '# as the delimiters.
Use a double-quoted here-string only if string expansion (interpolation) is needed; to selectively suppress expansion, escape $ chars. to be included verbatim as `$, as shown in your own answer.
String Literals in PowerShell
Get-Help about_quoting rules discusses the types of string literals supported by PowerShell:
To get a string with literal content (no interpolation, what C# would call a verbatim string), use single quotes: '...'
To embed ' chars. inside a '...' string, double them (''); all other chars. can be used as-is.
To get an expandable string (string interpolation), i.e., a string in which variable references (e.g., $var or ${var}) and expressions (e.g., $($var.Name)) can be embedded that are replaced with their values, use double quotes: "..."
To selectively suppress expansion, backtick-escape $ chars.; e.g., to prevent $var from being interpolated (expanded to its value) inside a "..." string, use `$var; to embed a literal backtick, use ``
For an overview of the rules of string expansion, see this answer.
Both fundamental types are also available as here-strings - in the forms #'<newline>...<newline>'# and #"<newline>...<newline>"# respectively (<newline> stands for an actual newline (line break)) - which make defining multi-line strings easier.
Important:
Nothing (except whitespace) must follow the opening delimiter - #' or #" - on the same line - the string's content must be defined on the following lines.
The closing delimiter - '# or "# (matching the opening delimiter) - must be at the very start of a line.
Here-strings defined in files invariably use the newline format of their enclosing file (CRLF vs. LF), whereas interactively defined ones always use LF only.
Examples:
# Single-quoted: literal:
PS> 'I am $HOME'
I am $HOME
# Double-quoted: expandable
PS> "I am $HOME"
I am C:\Users\jdoe
# Here-strings:
# Literal
PS> #'
I am
$HOME
'#
I am
$HOME
# Expandable
PS> #"
I am
$HOME
"#
I am
C:\Users\jdoe

Answer 2

I couldn't find this anywhere, but it appears every single variable in the script (string literal) has to be escaped with a tick like so. Instead of deleting the question I'll leave it up for a search hit.
$multiLineScript2 = #"
`$startDate2 = (get-date).AddDays($resultOfSubtraction).ToShortDateString();
`$endDate2 = (get-date).AddDays($resultOfSubtraction + 1).ToShortDateString();
"#