问题
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.
回答1:
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.
回答2:
You're close. You can strip the whitespace by using the replace method like this:
$answer.replace(' ','')
There needs to be no space or characters between the second set of quotes in the replace method (replacing the whitespace with nothing).
回答3:
You also have the Trim, TrimEnd and TrimStart methods of the System.String class. The trim method will strip whitespace (with a couple of Unicode quirks) from the leading and trailing portion of the string while allowing you to optionally specify the characters to remove.
#Note there are spaces at the beginning and end
Write-Host " ! This is a test string !%^ "
! This is a test string !%^
#Strips standard whitespace
Write-Host " ! This is a test string !%^ ".Trim()
! This is a test string !%^
#Strips the characters I specified
Write-Host " ! This is a test string !%^ ".Trim('!',' ')
This is a test string !%^
#Now removing ^ as well
Write-Host " ! This is a test string !%^ ".Trim('!',' ','^')
This is a test string !%
Write-Host " ! This is a test string !%^ ".Trim('!',' ','^','%')
This is a test string
#Powershell even casts strings to character arrays for you
Write-Host " ! This is a test string !%^ ".Trim('! ^%')
This is a test string
TrimStart and TrimEnd work the same way just only trimming the start or end of the string.
回答4:
You can use:
$answer.replace(' ' , '')
or
$answer -replace " ", ""
if you want to remove all whitespace you can use:
$answer -replace "\s", ""
回答5:
If the string is
$STR = 'HELLO WORLD'
and you want to remove the empty space between 'HELLO' and 'WORLD'
$STR.replace(' ','')
replace takes the string and replaces white space with empty string (of length 0), in other words the white space is just deleted.
来源：https://stackoverflow.com/questions/24355760/removing-spaces-from-a-variable-input-using-powershell-4-0