Clarification of nested IF and FOR statements

[findstr]

Hello!
I'm reading the book "The personal trainer: Windows command line".
It says that I need to use @ symbol to begin nested IF statement.

Use @ symbol to designate the start of the nested if statement.

Code: Select all

if "%1"=="1" ( 
    @if "%2"=="2" (hostname & ver) else (ver)
) else (
    hostname & ver & netstat -a
)

They also do the same with FOR statement:

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for /d %%B in (%APPDATA% %APPDATA%\*) do ( 
    @for %%C in ("%%B\*.txt") do (echo %%C)
)

I saw many examples on the Internet, where nested IF and FOR statements are used without @ symbol.
Do I need to use @ symbol to begin nested IF or FOR statement?
What is the difference between using @ symbol and not using it?
Thanks!

[findstr]

Also, what's the difference between goto LABEL and goto :LABEL?
Is is better to use : symbol with the name of the label?

[aGerman]

It says that I need to use @ symbol to begin nested IF statement.

Use @ symbol to designate the start of the nested if statement.

I never heard that @ "designates" something. The @ symbol prevents the prompt from getting displayed.
In a Batch script it's often used to suppress the prompt of the very first command which turns the prompt off for the rest of the script, namely "echo off".
In command line mode (rather than script mode) you may use it to suppress the repeated prompt for every command executed in a loop.

Code: Select all

for /l %i in (1,1,3) do @echo %i

Is is better to use : symbol with the name of the label?

It doesn't make any difference, except for the virtual :EOF label which requires the colon.

Steffen