唯尘

@echo off
set /p input=请输入需要检测的字符串：
set var=%input%
:sc_start
set var=%var:~0,-1%
set /a n+=1
if not "%var%"==""  (goto sc_start)
echo 字符串长度是%n%
pause>nul&exit

唯尘

@echo off&setlocal enabledelayedexpansion
set /p var=请输入需要判断的字符串：

:agin
set var=!var:~0,-1!
set /a n+=1
if not "!var!"=="" goto :agin

echo 字符串长度：!n!
pause>nul