How to escape a backslash in Powershell

Question

I\'m writing a powershell program to replace strings using

-replace \"$in\", \"$out\"

It doesn\'t work for strings containing a backslash,

Answer 1

The -replace operator uses regular expressions, which treat backslash as a special character. You can use double backslash to get a literal single backslash.

In your case, since you're using variables, I assume that you won't know the contents at design time. In this case, you should run it through [RegEx]::Escape():

-replace [RegEx]::Escape($in), "$out"

That method escapes any characters that are special to regex with whatever is needed to make them a literal match (other special characters include .,$,^,(),[], and more.