China DOS Union

This is how it is written in the book:

Run CHECKNEW.BAT from another batch program. In the parent batch program, you can include the command: call checknew

Suppose the parent batch program receives two replaceable parameters and wants to pass them to checknew.bat. You can use the command call checknew %1 %2 in the parent batch program.

Then I want to ask, in which aspect does the influence of these two %1 %2 parameters differ from the original without %1 %2? What can be done to the batch file with these parameters? Modify? Add? Or something else. Please give instructions and give an example, okay?????

%1, %2, ... are replaceable parameters, which are equivalent to memory variables. %1 is the first parameter after the command, %2 is the second parameter after the command. ... %n is the nth parameter. It can be replaced with actual parameters. For example, DIR /W /P, then %1 = W, %2 = P, and it can also be passed to a sub-batch program. This is particularly useful in batch files. For example, you create an A.BAT with the content: CALL DIR %1 %2, then you execute A /W /P which is equivalent to executing DIR /W /P. Or you create a B.BAT with the content:
IF %1=D GOTO 1
GOTO END
:1
DIR
:END
Then you execute B /D, which executes the DIR command.