UBound Return Discussion

[JohnOne]

I find myself wrapping UBound a lot of late, when working with a lot of arrays.

$str = "five words in this string"

$a = StringSplit($str, " ", 2)

MsgBox(0, "Upper Bound", _UBound($a))

Func _UBound(ByRef $array)
    Return UBound($array) - 1
EndFunc   ;==>_UBound

Why is that function called "UBound" anyway, it's more "Size" or "Length"

[czardas]

Why is that function called "UBound" anyway, it's more "Size" or "Length"

I believe it is short for Upper Bound.

[iamtheky]

Is it reasonable to lobby for @extended for stringsplit to be set to ubound($return) - 1  ?

[czardas]

Not unreasonable, but I think it might be a little expensive (not sure how much). Sometimes you already know the size of the returned array and want to avoid any extra overhead.

Edited December 12, 2015 by czardas

[iamtheky]

true, in most cases directly after stringsplit i have  $max = ubound($a) - 1 , that's been so ingrained I have no issue if there is even the slightest of penalty.

[JohnOne]

@extended is most likely set to 0 anyway, if that's true then setting it to the upper bound or length of the internal variant would not cost anything I believe.

[JohnOne]

I believe it is short for Upper Bound.

Yes, but It's not the upper bound is it, It's the size of the array, which is 1 more than the upper bound, and why -1 is needed.

[TheDcoder]

In the mean while, I simplified my code to 1 line

[czardas]

@JohnOne I get where you are coming from, however I tend to use both 0-based and 1-based arrays: depending on circumstances. I would consider a 0-based array to be the general case and Ubound defining the number of elements is easy to work with. When I declare / redim etc... I want to use the same definition for array size (measured by the number of elements) to maintain consistency.

Edit
I don't like the following syntax so much:

Redim $aColExpand [Ubound($aColExpand) +1][$iCols +1] ; maintain the same number of rows

 

Edited December 12, 2015 by czardas

[TheDcoder]

I think element 0 as a special place... similar to period 0 in schools where you get to do the pledge .

[JohnOne]

 

@JohnOne I get where you are coming from, however I tend to use both 0-based and 1-based arrays: depending on circumstances. I would consider a 0-based array to be the general case and Ubound defining the number of elements is easy to work with. When I declare / redim etc... I want to use the same definition for array size (measured by the number of elements) to maintain consistency.

It does not matter what index you use as your first, upper bound remains the same.

A full array iteration For To Loop wants the last element to be processed, to me that is the upper bound, not the one after it.

It's why I wrapped it, every loop has to have For $n = $x To Ubound($array) -1.

[czardas]

Look at my edit above. It is element zero that causes the issue. The definition of Ubound is not in any way to blame ambiguous or incorrect.

Edited December 12, 2015 by czardas

[JohnOne]

I know it's not ambiguous, it gives you what the help file says it does...

the size of the array dimension or the number of keys within a map

The size.

I'm saying it's wrong to call it UBound.

[czardas]

It is the upper bound if you number the elements starting from 1. I suppose you could define it as the last index number instead. Does anyone do that?

[JohnOne]

But you don't get to number the elements, AutoIt does that.

Local $Array[10] = [1,2,3,4,5,6,7,8,9,10]

For $i = 1 To UBound($Array)
    ConsoleWrite($i & " " & $Array[$i] & @LF)
Next

 

[czardas]

Okay I agree that the name UBound is an unfortunate choice, in so much as the convention of including an element numbered zero is inconsistent with the strict interpretation of the word bound. Think of a ruler with 12 inches: here the upper bound of the ruler is 12 and the lower bound is zero. An array with 12 elements would strictly speaking be analogous to to a ruler with 11 inches: confusing!

Edited December 12, 2015 by czardas

[TheDcoder]

 I got an idea for a new FAQ my Arrays 101 topic, Thanks JohnOne!

[water]

I think element 0 as a special place... similar to period 0 in schools where you get to do the pledge .

Element 0 has no special meaning in AutoIt. I once had a discussion with a Dev when rewriting the Excel or Word UDF (don't know which one).
It was clearly stated, that element 0 should not hold the element count. That's what UBound is made for.
How would you know if a function returns a 0- or 1-based array? Using 1-based arrays is bad coding practice I was told. Unfortunately some of my downloadable UDFs already used 1-based arrays.

[TheDcoder]

@water , I don't think 1 based arrays are not *that* bad... btw I know that element 0 has no special meaning but thinking it as special helps me a lot while coding !

[JohnOne]

Okay I agree that the name UBound is an unfortunate choice, in so much as the convention of including an element numbered zero is inconsistent with the strict interpretation of the word bound. Think of a ruler with 12 inches: here the upper bound of the ruler is 12 and the lower bound is zero. An array with 12 elements would strictly speaking be analogous to to a ruler with 11 inches: confusing!

lol, no no no, I'm not falling for that, a ruler has no 0th element

Maybe I just don't understand. perhaps someone could show me a couple of uses for Ubound on its own without deducting from it, maybe one which is not just for getting it's length, which is what a size should be for.