Switch imprecision

[Ontosy]

 

Dim $a=0
Switch $a
Case "test"
    ConsoleWrite("test")
Case 0
    ConsoleWrite(0)
Case "0"
    ConsoleWrite(2)
EndSwitch

Do it is normal that Switch fire "test" instead of 0 ?

[jchd]

The first Case is equivalent to this:

Local $a = 0
If $a = "test" Then ConsoleWrite("test")

Comparing a numerical entity with a text forces conversion of the text variable to numeric. "test" evaluates as 0, hence the comparison yields True and the ConsoleWrite is performed.

[AlessandroAvolio]

Sorry for double post, how can I delete?

Edited October 3, 2021 by AlessandroAvolio
double post

[AlessandroAvolio]

  

52 minutes ago, Ontosy said:

 

Dim $a=0
Switch $a
Case "test"
    ConsoleWrite("test")
Case 0
    ConsoleWrite(0)
Case "0"
    ConsoleWrite(2)
EndSwitch

Do it is normal that Switch fire "test" instead of 0 ?

 

Quote

Language Reference - Datatypes

If a string is used as a number, an implicit call to Number() function is done. So if it doesn't contain a valid number, it will be assumed to equal 0.

https://www.autoitscript.com/autoit3/docs/intro/lang_datatypes.htm

Quote

Switch...Case...EndSwitch

Parameters
<expression>    The value from the expression is then compared against the values of each case until a match is found.
<value>    The case is executed if the expression matches the value.

https://www.autoitscript.com/autoit3/docs/keywords/Switch.htm

Quote

Language Reference - Operators
AutoIt has the following assignment, mathematical, comparison, and logical operators.

    Comparison operators (case-insensitive if used with strings except for ==)
=    Tests if two VALUES are equal. e.g. If $vVar = 5 Then (true if $vVar equals 5). Case-insensitive when used with strings. See below about comparing with mixed datatypes.
==    Tests if two strings are equal. Case-sensitive. The left and right values are converted to strings if they are not strings already. This operator should only be used if string comparisons need to be case-sensitive.

Comparing different datatypes
Care is needed if comparing mixed datatypes, as unless the case-sensitive (==) string operator is used, mixed comparisons are usually made numerically. Most strings will be evaluated as 0 and so the result may well not be the one expected. 

https://www.autoitscript.com/autoit3/docs/intro/lang_operators.htm

Edited October 3, 2021 by AlessandroAvolio