Make variable all lower case in batch without call

Question

Here is a code I found to make a value lower case, but was curious how to do it without the CALL and just use a variable:

SET String=Hello, how are you ?
CALL :LoCase String
:LoCase
FOR %%i IN ("A=a" "B=b" "C=c" "D=d" "E=e" "F=f" "G=g" "H=h" "I=i" "J=j" "K=k" "L=l" "M=m" "N=n" "O=o" "P=p" "Q=q" "R=r" "S=s" "T=t" "U=u" "V=v" "W=w" "X=x" "Y=y" "Z=z") DO CALL SET "%1=%%%1:%%~i%%"
GOTO:EOF

Answer 1

I'm not sure which call you want to avoid - the one in the for loop or calling the subroutine. But it is possible to ditch both with macro and delayedExpansion which will be executed much faster:

@echo off

set locase=for /L %%n in (1 1 2) do if %%n==2 ( for %%# in (a b c d e f g h i j k l m n o p q r s t u v w x y z) do set "result=!result:%%#=%%#!") ELSE setlocal enableDelayedExpansion ^& set result=

set "string=SOme STrinG "
%locase%%string%

echo %result%

Also because of the way how replacement works in batch files you can just list the lower case letters - this will increase the performance also. Probably the code above is the fastest possible way to set string in lowercase only in batch file.