Using brackets to group expressions

by http://www.ss64.com/nt/index.html

Brackets can be useful to make complex commands more readable and/or to span commands across several lines.

      (command)

      (
        command )

e.g.
   IF EXIST C:\pagefile.sys (
                             ECHO pagefile found on C: drive)

The use of brackets is only required if the command is run over several lines e.g.

IF EXIST filename (
del filename
) ELSE (
echo The file was not found.
)

The IF statement does not use any great intelligence when evaluating Brackets, so for example the command below will fail:

IF EXIST MyFile.txt (ECHO Some(more)Potatoes)

This version will work:

IF EXIST MyFile.txt (ECHO Some[more]Potatoes)

It is worth noting that although brackets are legal in NTFS pathnames, such brackets will be misinterpreted by the command processor.

Testing Numeric values

Do not use brackets or quotes if you are comparing numeric values with an IF command
e.g.
IF (2) GEQ (15) echo "bigger"
or
IF "2" GEQ "15" echo "bigger"
Will perform a character comparison and will echo "bigger"
however the command
IF 2 GEQ 15 echo "bigger"
Will perform a numeric comparison and works as expected.

This is opposite to the SET /a command where quotes are required.