Clear all variables after each looping

Hi, I’m running a looped FISH script and would like to reset all variables, at the start of each iteration. Is there a command for clearing or reinitializing global and local variables during looping?

reset your variable at the beginning of the loop ?

fish define X
    loop
        variable = 0 
        ; your code 
    endloop
end

if there is a lot of variables, put them in a list.sequence() and reset them with a mini fish function ?