If True = "stringvalue" Then says it matches.

[BigDaddyO 81]

I accidently pulled the wrong value for a compare, but oddly it was showing as a Match so it wasn't until I reviewed my log files closely that I noticed a problem.

I was comparing a True value against a string value and it always came back as matching.

$PropertyValue = True
$Class = "String of characters"

If $PropertyValue = $Class Then
    ConsoleWrite("it matches?" & @CRLF)
Else
    ConsoleWrite("it DOESN'T Match" & @CRLF)
EndIf

 

I've corrected my code to pull the proper string value for $PropertyValue but just wondering why this was happening.

Thanks,
Mike

[Melba23 3,799]

BigDaddyO,

When you make a comparison AutoIt will convert the second variable into the same datatype as the first - in this case a string into a Boolean. And as any string other than empty will convert to True, you get the match.

Look in the Help file under <Language Reference - Operators> - the bottom of the page for more info.

Top Tip: Never mix datatypes in comparisons - always force to a single datatype.

M23

Edit: Also look under <Language Reference - Datatypes> - Boolean section.

Edited December 30, 2021 by Melba23

[Deye 126]

Used alot In autoit code as we know it = the rule is that anything that is not equal to "0" or "" (empty string) automatically turns out to be true 

[jchd 1,823]

4 hours ago, Melba23 said:

When you make a comparison AutoIt will convert the second variable into the same datatype as the first

Not completely true:

vd(1 = "1")
vd("1" = 1)
vd(1 = "0")
vd("0" = 1)
vd(1 = "True")
vd("True" = 1)
vd(1 = "False")
vd("False" = 1)
vd(True = "True")
vd("True" = True)
vd(True = "False")
vd("False" = True)
vd(String(True))
vd(Number("True"))
vd(Number("False"))
vd(Number("abc"))
vd(("True" ? 1 : 0))
vd(("False" ? 1 : 0))

The function vd() is a variable dump, showing datatype and value. Results are:

Boolean            True
Boolean            True
Boolean            False
Boolean            False
Boolean            False
Boolean            False
Boolean            False
Boolean            False
Boolean            True
Boolean            True
Boolean            True
Boolean            True
String (4)         'True'
Double             0.0
Double             0.0
Int32              0
Int32              1
Int32              1

If AutoIt was to convert the second operand to the datatype of the first, then "False" = True would yield False, which isn't the case.

Interestingly, Number() returns a double when fed with the strings "True" or "False", in contradiction with the default (integer) claimed in the help.