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;loops from start to stop (inclusive) with the given step
for(ByRef LoopVariable, start, stop, ByRef step)
{
    if (!step)
        step := (start <= stop ? 1 : -1)

    LoopVariable := start

    return floor((stop - start) / step) + 1
}

;loops from start to stop (exclusive) with the given step
forE(ByRef LoopVariable, start, stop, ByRef step)
{
    if (!step)
        step := (start <= stop ? 1 : -1)

    LoopVariable := start

    return ceil((stop - start) / step)
}

;loops zero times (start < stop, but step is negative)
Loop, % for(i, 5, 7, step := -1)
{
    MsgBox, % i

    i += step
}


;loops zero times (start > stop, but step is positive)
Loop, % for(i, 3, -1, step := 2)
{
    MsgBox, % i

    i += step
}

Loop, % for(i, 1, 7, step := 2)
{
    if (i = 3)
    {
        ;don't forget to increment the value before continuing
        i += step

        continue
    }

    MsgBox, % i

    i += step
}

/*
General form

Loop, % for(LoopVariable, start, end, IncrementVariable := step)
{
    ;loop code goes here

    LoopVariable += IncrementVariable
}


or if IncrementVariable already contains the step

Loop, % for(LoopVariable, start, end, IncrementVariable)
{
    ;loop code goes here

    LoopVariable += IncrementVariable
}
*/


;if !step (0 or blank), 1 is used if start <= stop, and -1 if start > stop
MsgBox, % "Loop from -1 to 3 (inclusive), step 1"

;IncrementVariable can be set to a function's return
;func() returns "" - so 1 will be used as the step (since start <= stop)
Loop, % for(i, -1, 3, step := func())
{
    MsgBox, % i

    i += step
}


;if !step (0 or blank), 1 is used if start <= stop, and -1 if start > stop
MsgBox, % "Loop from 3 to -1 (exclusive), step -1"

;-1 will be used as the step (since start > stop)
Loop, % forE(i, 3, -1, step := 0)
{
    MsgBox, % i

    i += step
}


MsgBox, % "Loop from 0 to -2 (inclusive), step 2 (loops zero times)"

Loop, % for(i, 0, -2, step := 2)
{
    MsgBox, % i

    i += step
}


MsgBox, % "Loop from 1 to 5 (inclusive), step 2"

Loop, % for(i, 1, 5, step := 2)
{
    MsgBox, % i

    i += step
}


MsgBox, % "Loop from 6 to 3 (exclusive), step -3"

Loop, % forE(i, 6, 3, step := -3)
{
    MsgBox, % i

    i += step
}


MsgBox, % "Loop from -5 to -2 (inclusive), step 2"

Loop, % for(i, -5, -2, step := 2)
{
    MsgBox, % i

    i += step
}


;even works for decimals
MsgBox, % "Loop from 0.2 to 0.95 (exclusive), step 0.25"

Loop, % forE(i, 0.2, 0.95, step := 0.25)
{
    MsgBox, % i

    i += step
}

return

;returns the empty string - used as the step for first loop
func()
{
}

;an example showing nested for loops - no difference in syntax
;note: you can use an the outer loop's variable as either
;   the start, stop, or step for an inner loop.

;number of times to loop
n := 5

MsgBox, % "Nested loop:`n"
    . "i loops from 1 to n (inclusive), step 1`n"
    . "j loops from i to n (exclusive), step 1`n"

loop, % for(i, 1, n, i_step := 1)
{
    loop, % forE(j, i, n, j_step := 1)
    {
        MsgBox, % "i: " . i . "`n"
            . "j: " . j
               
        j += j_step
    }

    i += i_step
}