How do I add a variable's number to another variable in batch?

Question

So, I'm making a game with income (variable) and every turn the money variable goes up, as much as the income variable is for example:

set income=350
set /a "money=money+INCOME"

If I use the normal %VARIABLENAME% to call the variable it doesn't work and the money value stays the same. Please help!

Ah, the classic [delayed expansion trap](http://stackoverflow.com/questions/30282784/combining-all-mp4s-in-directory-with-ffmpeg/30284028#30284028). Add `setlocal enabledelayedexpansion` to the start of your script and change `%money%` to `!money!`. — SomethingDark, Jul 03 '15 at 02:01
Please answer using an answer, even if you are going to use a link. — ender_scythe, Jul 03 '15 at 02:09
Please specify your question, if you mean that it would be: `:LOOP........ set BLAHBLAH............. goto LOOP` it's not — ender_scythe, Jul 03 '15 at 02:15
Are you certain that `set /a "money=%money%+%income%"` doesn't work? This works correctly on my machine. Unless it's inside the parentheses of a `FOR ... DO (...)` loop. Then it's the delayed expansion problem. — Ryan Bemrose, Jul 03 '15 at 02:27

UnknownOctopus · Accepted Answer · 2015-08-12T05:35:40.773

1

Your issue could be caused by delayed expansion.

This alternate script should work for you:

@echo off

set money=20 

set income=30

set /a money+=%income% 

pause

edited Aug 12 '15 at 05:35

answered Jul 03 '15 at 02:03

UnknownOctopus

1

The /a for setting values is unnecessary! – ender_scythe Jul 03 '15 at 02:19
This solution has nothing to do with delayed expansion. – Ryan Bemrose Jul 03 '15 at 02:28
I'm saying OP's problem was caused by delayed expansion – UnknownOctopus Jul 03 '15 at 02:37
But you don't say how to solve it; you just remove the circumstances that require it in the first place, which won't address the actual problem. – SomethingDark Jul 03 '15 at 02:39
I included a link about delayed expansion, then offered an alternate solution – UnknownOctopus Jul 03 '15 at 02:41
Unlike `set /a money+=%income%`, the `set /a "money+=income"` works whether _delayed expansion_ is disabled or enabled. And BTW: it means take the value of `income` and add it to `money` variable and keeps `income` unchanged: the same as `set /a "money=money+income"`. – JosefZ Jul 03 '15 at 06:46
Doing math (4*4, 6/2, etc.) requires a `set /a "MATHHERE"` – ender_scythe Jul 03 '15 at 16:24

1 Answers1