maColLen = maColLen * (maCol = maCol[1]) + 1 is working differently PRT 11/10

Yeah, I tried that too (just above the maColLen = maColLen * (maCol = maCol[1]) + 1), but it’s always undefined.

Thank you for the correction proposal to make it works.
Ok it works now… And I can understand the correction.

// Settings
once maLen = 20
once maType = 1

if barindex > maLen then
   // Indicators
   ma = Average[maLen, maType](close)
 
   // Color of ma line
   if(ma > ma[1]) then
      maCol = +1
   elsif(ma < ma[1]) then
      maCol = -1
   else
      maCol = 0
   endif
 
   // this variable should give me the distance from the last changement of color
   maColLen = maColLen * (maCol = maCol[1]) + 1
endif
return maColLen, maCol

But I still don’t completely get why they reacted differently.
So I have done some research on that and now I think i’m getting closer at why at low level it’s working differently.

Fact 1:

PRT 10 and 11 behaves completely differently when it comes to compare a value with the undefined.

myvar = undefined
return myvar = 4

This is returning undefined on PRT v10 and zero on PRT v11…

Fact 2:

A simple variable as maColLen by default (if not used with a function like average on the right of assignement) is 0, and you can prove that with that indicator (which returns 0 both on PRT 10 and 11):

myVar = myVar
return myVar

Fact 3:

A simple variable as maCol if it’s set equals to maCol[1] on first bars will give you undefined (both on 10 an 11):

myVar = myVar[1]
return myVar

So now that I have those fact in mind we have three cases:

• bars < 20
  • ma is undefined
  • maCol is undefined (for fact 3, for the else line of ma color)
  • so maColLen = maColLen * (maCol = maCol[1]) + 1 —> maColLen = 0 * (undefined) + 1   on PRT 10 and    maColLen = 0 * (0) + 1  on PRT 11
• bars = 20
  • ma is a value but ma[1] is not a value
  • maCol is undefined (for fact 3, for the else line of ma color)
  • so maColLen = maColLen * (maCol = maCol[1]) + 1 —> maColLen = 0 * (undefined) + 1   on PRT 10 and    maColLen = 0 * (0) + 1  on PRT 11
• bars > 20
  • ma and ma[1] is a value
  • maCol is a value +1, -1 (i’ll not consider the ema to be flat between bar 20 and 21)
  • so maColLen = maColLen * (maCol = maCol[1]) + 1 —> maColLen = 0 * (a value) + 1   —> why at this point PRT 10 should not work? I don’t get this…

Is this all correct? Or I’m wrong at a certain step?
I’m not getting why PRT 10 is not giving values… i.e. why on the bulleted list above “bars > 20”, point third is still not working on v10.
I just wish I had a better understanding of what’s going on.
Thanks again for your patience.