Removing spaces from a variable input using PowerShell 4.0

string powershell variables spaces stripping
cloudnyn3 picture cloudnyn3 · Jun 22, 2014 · Viewed 188.6k times · Source

I've tried a few things already but they don't seem to work for some reason.

Basically what I'm attempting to do is have a user input a value using the "Read-host" cmdlet, then strip it of any spaces.

I tried:

$answer = read-host
$answer.replace(' ' , '""')

And:

$answer = read-host
$answer -replace (' ')

I'm probably missing something really obvious, but if anyone could help me out or show me an easier way to achieve this I would appreciate it.

I was going to pipeline the variable to a command and strip it in that fashion, but none of the examples I've seen work, although they look much easier.

Answer

filimonic picture filimonic · Jun 23, 2014

The Replace operator means Replace something with something else; do not be confused with removal functionality.

Also you should send the result processed by the operator to a variable or to another operator. Neither .Replace(), nor -replace modifies the original variable.

To remove all spaces, use 'Replace any space symbol with empty string'

$string = $string -replace '\s',''

To remove all spaces at the beginning and end of the line, and replace all double-and-more-spaces or tab symbols to spacebar symbol, use

$string = $string -replace '(^\s+|\s+$)','' -replace '\s+',' '

or the more native System.String method

$string = $string.Trim()

Regexp is preferred, because ' ' means only 'spacebar' symbol, and '\s' means 'spacebar, tab and other space symbols'. Note that $string.Replace() does 'Normal' replace, and $string -replace does RegEx replace, which is more heavy but more functional.

Note that RegEx have some special symbols like dot (.), braces ([]()), slashes (\), hats (^), mathematical signs (+-) or dollar signs ($) that need do be escaped. ( 'my.space.com' -replace '\.','-' => 'my-space-com'. A dollar sign with a number (ex $1) must be used on a right part with care

'2033' -replace '(\d+)',$( 'Data: $1')
Data: 2033

UPDATE: You can also use $str = $str.Trim(), along with TrimEnd() and TrimStart(). Read more at System.String MSDN page.

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