LoopIndex and LoopLength Query

I'm having a bit of a trouble getting LoopIndex and LoopLength to work as expected - LoopLength first:

Say I have a condition of For "TestLoop" from 0 to 1 - I'd assume LoopLength("TestLoop") would be 2, since the system would first run through loop 0 and then loop 1, however LoopLength returns 1.

If the condition is For "TestLoop" from 1 to 2, it returns 2 as expected. Does looping only work for positive integers?

As for LoopIndex, does it return the currently processed loop number or the nth iteration of a loop? Say if I have For "TestLoop" from 2 to 3 and I have an action that makes use of LoopIndex("TestLoop") and the system is running through the first loop (number 2), would LoopIndex return 1 or 2?

Sorry for possibly asking obvious questions, but the Wiki is very scarce on the topic of loop evaluation. Using Construct Classic 1.2

Well, it appears that looplength just returns the end number of the loop. Loopindex will return the currently processed loop number.

ex:

for 1 to 5

1,2,3,4,5

for 1 to -2

1,0,-1,-2

for 0 to 3

0,1,2,3

Thank you. That clears things up quite a bit.