please explaine this for me

[Mohammad_Dos]

hi. I dont know much from Dos.
please explaine me this. line by line


@echo off
:aa
echo 1 = 1
echo 2 = 2
echo 3 = 3
echo 4 = 4
echo 5 = exit
set /p yy=selection:
if %yy% equ 5 goto :ex
rem null option to exit?
if "%yy%" equ "" goto :ex
set yy=:menu%yy%
call %yy%
rem loop option here, or "goto :ex" for no loop
goto :aa

:menu1

goto :menux
:menu2

goto :menux
:menu3

goto :menux
:menu4

goto :menux

:ex
exit
:menux

[orange_batch]

hi. I dont know much from Dos.
please explaine me this. line by line

Okay.

@echo off

Prevents the commands in your script from being displayed in the Command Prompt window.

:aa

This is a label "aa" in your script which you can begin processing from at any time with "goto aa".

echo 1 = 1

This displays "1 = 1" in the Command Prompt window.

echo 2 = 2

Same as above, except "2 = 2".

echo 3 = 3

Same.

echo 4 = 4

Same.

echo 5 = exit

This displays "5 = exit". These are not commands, just text.

set /p yy=selection:

This displays "selection:" in the Command Prompt window and waits for you to type something and press enter.
Then it sets the variable "yy" to whatever you typed.

if %yy% equ 5 goto :ex

If the value of the variable "yy" is equal to 5, go to the label "ex".

rem null option to exit?

"rem" is like "echo", except no text is displayed in the Command Prompt window.
It is used for comments inside the script, or disabling a line of code.

if "%yy%" equ "" goto :ex

If the value of the variable "yy" with surrounding quotes is equal to "", that is, nothing, go to the label "ex".

set yy=:menu%yy%

Set the variable "yy" to ":menu" and it's own current value.
In other words, prefix ":menu" onto itself.

call %yy%

Executes the value of "yy" as a command. Using "call" may be unnecessary here.

rem loop option here, or "goto :ex" for no loop

Another comment.

goto :aa

Go to the aforementioned label "aa".

:menu1

This is the label "menu1".

goto :menux

This goes to the label "menux".

:menu2

This is the label "menu2".

goto :menux

This goes to the label "menux".

:menu3

Again...

goto :menux

Again...

:menu4

Again...

goto :menux

Again...

:ex

This is the label "ex".

exit

This closes the current Command Prompt session (cmd.exe).

:menux

This is the label "menux".

[Mohammad_Dos]

thanks a lot