Change variable of for statement inside for function

myrain25

how can i change the variable inside the the statement

for i=1, 10 do
print(i)
i = 9
end

why i can't change "i" variable on that for declaration
because that function always execute for function for 10 times..

OZApps

if you want to exit the loop, try using break instead. You can also try to use things like

if i==3 then break end

.

For loops in Lua are different than C or many other language loops.

HubertRonald

Hi @myrain25 you have to be careful with this, check these little codes:

--------------- --case 1 --------------- a={...} for i=1, 10 do a[i]=i end   count=1 for i=1,#a do i=nil print(i,a[i],a[count]) count = count + 1 end   --[[ got: ----------------------- i a[i] a[count] ----------------------- nil nil 1 nil nil 2 nil nil 3 nil nil 4 nil nil 5 nil nil 6 nil nil 7 nil nil 8 nil nil 9 nil nil 10 ----------------------- ]]     --------------- --case 2 --------------- a={...} for i=1, 10 do a[i]=i end   count=1 for k,v in pairs(a) do v="e" k=nil print(k,v,a[k],a[count]) count = count + 1 end   --[[ got: ----------------------------- k v a[k] a[count] ----------------------------- nil e nil 1 nil e nil 2 nil e nil 3 nil e nil 4 nil e nil 5 nil e nil 6 nil e nil 7 nil e nil 8 nil e nil 9 nil e nil 10 ----------------------------- ]]

This can give you a headache when you work with Box2D in destroying objects :-S

atilim

Copy paste from the book 'Programming in Lua':

You should never change the value of the control variable: the effect of
such changes is unpredictable. If you want to end a for loop before its normal
termination, use break.