How to concatenate strings in windows batch file for loop?

I'm familiar with Unix shell scripting, but new to windows scripting.

I have a list of strings containing str1, str2, str3...str10. I want to do like this:

for string in string_list
do
  var = string+"xyz"
  svn co var
end

I do found some thread describing how to concatenate string in batch file. But it somehow doesn't work in for loop. So I'm still confusing about the batch syntax.

Try this, with strings:

set "var=string1string2string3"

and with string variables:

set "var=%string1%%string2%%string3%"

In batch you could do it like this:

@echo off

setlocal EnableDelayedExpansion

set "string_list=str1 str2 str3 ... str10"

for %%s in (%string_list%) do (
  set "var=%%sxyz"
  svn co "!var!"
)

If you don't need the variable !var! elsewhere in the loop, you could simplify that to

@echo off

setlocal

set "string_list=str1 str2 str3 ... str10"

for %%s in (%string_list%) do svn co "%%sxyz"

However, like C.B. I'd prefer PowerShell if at all possible:

$string_list = 'str1', 'str2', 'str3', ... 'str10'

$string_list | ForEach-Object {
  $var = "${_}xyz"   # alternatively: $var = $_ + 'xyz'
  svn co $var
}

Again, this could be simplified if you don't need $var elsewhere in the loop:

$string_list = 'str1', 'str2', 'str3', ... 'str10'
$string_list | ForEach-Object { svn co "${_}xyz" }

A very simple example:

SET a=Hello
SET b=World
SET c=%a% %b%!
echo %c%

The result should be:

Hello World!