Update wiki example for 2d arrays - suggestion

[Myicq]

I had a need today to make 2d arrays. Could not remember how, so on to the Wiki.

It's all nicely explained, BUT unfortunately I was in doubt which parameter is rows, which is columns.

The Wiki shows example of [3][3], which does not explain much. Nothing is mentioned about the order.

May I suggest to update Wiki to show example for something like [3][5] and clearly indicate which of 3 is rows, which is columns ?

Just a suggestion, really

Thanks

[willichan]

The standard convention is rows then columns, but it doesn't really matter.  As long as your script is consistant in the way it uses the array, you can order them either way.

[guinness]

All users have access to edit the wiki. So there was no need to request.

[MvGulik]

*Scratches head*. ... http://www.mediawiki.org/wiki/Help:Tables

Oops. Brain lock on wrong language.

Edited December 7, 2014 by MvGulik

[water]

I think the concept of arrays is perfectly described in the help file.

Edited December 6, 2014 by water

[LarsJ]

What about the last line in the link above: "The use of an Array inside another Array can affect the execution speed of your script." Is this correct? I don't think so.

[water]

Why do you think it doesn't?

[LarsJ]

In the three examples below there are three arrays with an integer, a string, and an array (an array inside another array). In the loops a variable is assigned the content of the integer, string and array.

Example1 is the fastest and Example3 is the slowest. But the time increase from Example2 (string) to Example3 (array) is not much bigger than the time increase from Example1 (integer) to Example2 (string).

Conclusion: The time increase for using an array inside an array is not significant, compared to using other data types (strings, floats) inside an array.

 

Example1()
Example2()
Example3()

Func Example1()
  Local $v, $i = 3, $a1[4] = [ 1, 2, $i, 4 ]
  Local $hTimer = TimerInit()
  For $i = 1 To 100000
    $v = $a1[2] ; $v = $i
  Next
  ConsoleWrite( "Time (integer) = " & TimerDiff( $hTimer ) & @CRLF )
EndFunc

Func Example2()
  Local $v, $s = "This is a string", $a1[4] = [ 1, 2, $s, 4 ]
  Local $hTimer = TimerInit()
  For $i = 1 To 100000
    $v = $a1[2] ; $v = $s
  Next
  ConsoleWrite( "Time (string) = " & TimerDiff( $hTimer ) & @CRLF )
EndFunc

Func Example3()
  Local $v, $a2[4] = [ 1, 2, 3, 4 ], $a1[4] = [ 1, 2, $a2, 4 ]
  Local $hTimer = TimerInit()
  For $i = 1 To 100000
    $v = $a1[2] ; $v = $a2
  Next
  ConsoleWrite( "Time (array) = " & TimerDiff( $hTimer ) & @CRLF )
EndFunc

[kylomas]

LarsJ,

I get these results (Win7 x64)...

Time (integer) = 53.3489817378393
Time (string)  = 69.3359536534167
Time (array)   = 89.7996557876123

[JLogan3o13]

Ditto on 8.1 x64. Difference is not huge for this example, but enough that I think the statement is valid.

[LarsJ]

I just think it's a pity that a lot of AutoIt users avoid to use this nice feature (arrays inside an array) because of this warning. They think the loops to handle the arrays will be running for 20 seconds more. The fact is that they probably only will be running for 20 milli seconds more.

I've used this feature a lot (since version 3.6). I've never experienced performance issues. When I have performance issues with arrays, it's nearly always caused by the ReDim statement.

[Melba23]

LarsJ,

I will amend the Help file text to reflect the current situation reflected by the results posted above - which match my own tests.

M23

Edit: "An array stored inside another array can be accessed directly, but this method is slightly slower than accessing other datatypes:"

Edited December 9, 2014 by Melba23

[LarsJ]

Melba23, Thank you. I think this is much better.