What's the difference between single quote and double quote to define a string in powershell

Solution 1:

Double quotes allow variable expansion while single quotes do not:

PS C:\Users\Administrator> $mycolor="red"
PS C:\Users\Administrator> write-output -inputobject 'My favorite color is $mycolor'
My favorite color is $mycolor

Source: http://www.techotopia.com/index.php/Windows_PowerShell_1.0_String_Quoting_and_Escape_Sequences

(I know version 1.0 but the principle is still the same)

Solution 2:

This is not trying to be a better answer. Just another way to say it.

The variable expansion between apostrophes and quotes are the same as on UNIX shells (sh, ksh, bash). Using apostrophes will take the character string as-is, without processing any escapes.

PS C:\Users\lit> $x = "`t"
PS C:\Users\lit> $x

PS C:\Users\lit> Write-Output "now${x}is"
now     is
PS C:\Users\lit> $x = '`t'
PS C:\Users\lit> $x
`t
PS C:\Users\lit> Write-Output "now${x}is"
now`tis
PS C:\Users\lit> $word = "easy"
PS C:\Users\lit> "PowerShell is $word"
PowerShell is easy
PS C:\Users\lit> 'PowerShell is $word'
PowerShell is $word