Condition

IF NOT ERRORLEVEL 1 echo OK

Concatenation

SETLOCAL ENABLEDELAYEDEXPANSION 
SET CLASSPATH=
FOR %%I IN (*.jar) DO (
SET CLASSPATH=!CLASSPATH!%%~fI;
)

Replace

set TEST=c:\Windows\tmp
set TEST2=%TEST:\=/%
echo %TEST2%
REM c:/Windows/tmp 

Loop

REM Simple loop (1 to 5)
FOR /L %%I IN (1,1,5) DO (
	echo %%I
)
 
REM filename list without path
FOR %%I IN (*.txt) DO (
    echo %%~nxI
)
 
REM filename list with path
FOR %%I IN (*.txt) DO (
    echo %%~fI
)
 
REM Directory list (recursive)
FOR /R C:\ %%I IN (*) DO (
    echo %%~pI
)
 
REM filename pattern list (recursive)
FOR /R C:\ %%I IN (*.txt) DO (
    echo %%I
)

Output redirection

# Standard output
filename.exe > NUL
 
# Standard output and Error output
filename.exe > NUL 2&>1

FAQs

Variables

REM Display the current directory
echo %CD%
REM data time
echo %DATE% %TIME%
REM random 	between 0 and 32767
echo %RANDOM%

How put a date in variable

FOR /F "tokens=1-3 delims=/ " %%i IN ('DATE /T') DO (
	SET DATUM=%%k-%%j-%%i
)