Batch file game trouble, missing operator error - batch-file

Question

I've been working on a batch file game for some time, but I am having trouble with the shop I am making. When I run the script and try to buy something in the shop it gives me "missing operator" and then displays the message for buying the item, but doesn't add the item to the player's inventory. Heres the code. Any help is much appreciated.
:w_shop
title Nova: In the Weapon Shop
:sword_screen
cls
echo.
echo You have %money% gold.
echo.
echo What will you buy?
echo 1) Wooden Sword: 500 gold
echo You own %sword1%
echo.
echo 2) Stone Sword: 1000 gold
echo You own %sword2%
echo.
echo 3) Iron Blade: 5000 gold
echo You own %sword3%
echo.
echo 4) Mythril Sabre: 7500 gold
echo You own %sword4%
echo.
echo 5) Mythril Longsword: 10000 gold
echo You own %sword5%
echo.
echo 6) Next
echo.
echo 7) Leave Shop
set/p sword_screen=
if %sword_screen% LEQ 0 goto sword_screen
if %sword_screen% GEQ 8 goto sword_screen
if %sword_screen% EQU 1 goto buy_sword1
if %sword_screen% EQU 2 goto buy_sword2
if %sword_screen% EQU 3 goto buy_sword3
if %sword_screen% EQU 4 goto buy_sword4
if %sword_screen% EQU 5 goto buy_sword5
if %sword_screen% EQU 6 goto gauntlet_screen
if %sword_screen% EQU 7 goto main_menu
:buy_sword1
set price=500
set att=100
if %money% LSS %price% goto lack_funds
set/a money=%money%-%price%
set/a %sword1%=%sword1%+1
echo.
echo You bought a Wooden Sword. This weapon has %att% attack.
pause>nul
goto sword_screen
:buy_sword2
set price=1000
set att=150
if %money% LSS %price% goto lack_funds
set /a money=%money%-%price%
set /a %sword2%=%sword2%+1
echo.
echo You bought a Stone Sword. This weapon has %att% attack.
pause>nul
goto sword_screen
:buy_sword3
set price=5000
set att=300
if %money% LSS %price% goto lack_funds
set /a money=%money%-%price%
set /a %sword3%=%sword3%+1
echo.
echo You bought a Iron Blade. This weapon has %att% attack.
pause>nul
goto sword_screen
:buy_sword4
set price=7500
set att=500
if %money% LSS %price% goto lack_funds
set /a money=%money%-%price%
set /a %sword4%=%sword4%+1
echo.
echo You bought a Mythril Sabre. This weapon has %att% attack.
pause>nul
goto sword_screen
:buy_sword5
set /a price=10000
set /a att=1000
if %money% LSS %price% goto lack_funds
set /a money=%money%-%price%
set /a %sword5%=%sword5%+1
echo.
echo You bought a Mythril Longsword. This weapon has %att% attack.
pause>nul
goto sword_screen
Just to be clear, the sword variables and the money variable are declared earlier on in the code

Answer 1

since you did not define money nor sword variables the lines
if %money% LSS %price% goto lack_funds
set/a %sword1%=%sword1%+1
expand to
if LSS 500 goto lack_funds
set/a =+1
which is wrong. Those are common mistakes. change the line like this:
if [%money%] LSS [%price%] goto lack_funds
set/a sword1=0%sword1%+1
Note that the variables are surrounded by square brackets so even if the variable is undefinde you'll get at least a valid line
Note that the left-param in the set-line must not have the %-signs and the right-param has an additional 0 so that if the variable is undefined you'll get 0+1 which is valid
btw, there is not lack_funds lable in your code snippet and also i recommend adding
echo off
set money=5000
at the beginning of the script