Calculating the sum of two variables in a batch script

Question

This is my first time on Stack Overflow so please be lenient with this question. I have been experimenting with programming with batch and using DOSbox to run them on my linux machine.

Here is the code I have been using:

@echo off set a=3 set b=4 set c=%a%+%b% echo %c% set d=%c%+1 echo %d% 

The output of that is:

3+4 3+4+1 

How would I add the two variables instead of echoing that string?

Answer 1

You need to use the property /a on the set command.

For example,

set /a "c=%a%+%b%" 

This allows you to use arithmetic expressions in the set command, rather than simple concatenation.

Your code would then be:

@set a=3 @set b=4 @set /a "c=%a%+%b%" echo %c% @set /a "d=%c%+1" echo %d% 

and would output:

7 8