Why does a string used in an expression return 0?

[InunoTaishou]

Absolutely, something like that should definitely not work. To the wrong person that could be considered a map or dictionary but it is definitely not.

[czardas]

@InunoTaishou That's a good point!

[jchd]

I beg to differ: the behavior matches the specified conversion conventions of AutoIt (in this case, Number() specification) and, frankly I find that pretty logical (from the AutoIt point of view).

[InunoTaishou]

I know AutoIt is very forgiving but I feel like that shouldn't make sense (and doesn't to me). I'd expect number() to return the int/float value of a string representation of a number. Not capture numbers up until a non numeric value.

Global $sString = "32 Apples and 43 oranges"
ConsoleWrite(Number($sString) & @LF)

I've never used it in this sense but even though it starts with a number this should fail because it is a full blown string sentence.

Global $sString = "32 Apples and 43 oranges"
ConsoleWrite(IsNumber($sString) & @LF)

Should act like this. IsNumber says this is not a number, even though Number() would return 32. If someone was expecting some numbers in a string but IsNumber says it's not one, the programmer would have some warning about needing numbers, or use a regular expression to get the numbers from a string (if they wanted to do so)

#include <Array.au3>

Global $sString = "32 Apples and 43 oranges"
Global $aRegExp = Null

If (IsNumber($sString)) Then
    ConsoleWrite($sString & @LF)
Else
    $aRegExp = StringRegExp($sString, "\d+", 3)
    ConsoleWrite(_ArrayToString($aRegExp, ", ") & @LF)
EndIf

 

[czardas]

1 hour ago, jchd said:

I beg to differ: the behavior matches the specified conversion conventions of AutoIt (in this case, Number() specification) and, frankly I find that pretty logical (from the AutoIt point of view).

Exceptions aside!

MsgBox('0.1e+001', 'OK / Cancel ???', Number('0.1e+001'))

This proves that the conversion  is inconsistent.

[jchd]

9 hours ago, InunoTaishou said:

I know AutoIt is very forgiving but I feel like that shouldn't make sense (and doesn't to me). I'd expect number() to return the int/float value of a string representation of a number. Not capture numbers up until a non numeric value.

Ever wrote a little C/C++ program and used atoi()? http://www.cplusplus.com/reference/cstdlib/atoi/

That behavior is pretty standard in many programming languages and doing so AutoIt didn't create a new path in wild forest but highways with common signs and heavy traffic.

8 hours ago, czardas said:

This proves that the conversion  is inconsistent.

??? Which inconsistancy?

 

[czardas]

53 minutes ago, jchd said:

??? Which inconsistancy?

If the internal conversion was using the same algorithm as Number(), then the message box would contain both OK and Cancel buttons. I only get an OK button, which implies that Number() is inconsistent with the internal numeric conversion (in this instance). We've discussed several inconsistencies with AutoIt over the years and this is just another one of them. Perhaps it seems trivial, but it's still a fact.

Edited April 23, 2017 by czardas

[jchd]

Fact?

Can you please reread the help under MsgBox, in particular the constants for parameter "flag".

[czardas]

I'm not sure what you are getting at, perhaps we are talking about two different things.

$MB_OKCANCEL = 1
Number('0.1e+001') = 1
MsgBox'(0.1e+001', '', '') does not give $MB_OKCANCEL style.

Internal conversion is different to Number() as it is implemented in AutoIt on my machine. I only mentioned it because I thought you stated something to the contrary which I deemed to be incorrect.

Edited April 23, 2017 by czardas

[jchd]

I apologize for responding too fast, was looking at return values not flag.

Yeah, that sound a bit strange. Clearly the conversion isn't done the same way here. Nonetheless, passing a flag (integer) value as a string containing a float in scientific notation isn't that common in solid code. We (non-DEVs) can do nothing against that but I wouldn't loose much if it wasn't fixed within hours.

[czardas]

4 minutes ago, jchd said:

I wouldn't loose much if it wasn't fixed within hours.

Me niether.

[iamtheky]

can someone pop the hood and tell us exactly what is happening with the string values that you use to declare an array / set parameters?

As best I can tell it performs a string left up to the first non 0-9 character, then performs a number() on that string.

[jchd]

I suppose it just uses the result of Number().

[InunoTaishou]

7 hours ago, jchd said:

Ever wrote a little C/C++ program and used atoi()? http://www.cplusplus.com/reference/cstdlib/atoi/

 

Actually only used stoi and never used it on a string starting with numbers. I was wrong.

Edited April 23, 2017 by InunoTaishou

[iamtheky]

2 hours ago, jchd said:

I suppose it just uses the result of Number().

but it doesn't, as evidenced by @czardas

It evaluates that scientific string as 0 because that is the only value prior to a non 0-9 character '.'  put any other number (even zero padded numbers) before the decimal point and you will get that number, which is absolutely not the behavior of number() so there has to be formatting of that string happening prior.

Edited April 23, 2017 by iamtheky

[jchd]

Indeed, scientific notation isn't parsed correctly in these cases.