1 and 0 are not true and false?

Warhaven · February 25, 2010, 6:08pm

I kept getting an error in my program when it would check for the state of a button. So, I tested something…

set foo to 1
if foo then
	display dialog "True!"
end if

I get an error saying it can’t turn 1 into a boolean.

Seriously? I never noticed this before, and it completely floors me. I’m pretty sure this makes AppleScript the only language in the history of computer programming where true and false do not equal 1 and 0.

StefanK · February 25, 2010, 6:16pm

Hi,

it’s right, 1 is an integer number, to test a boolean value you must coerce it


set foo to 1
if (foo as boolean) then
	display dialog "True!"
end if

Unlike other languages, where true means “not zero”, AppleScript distinguishes numeric and booelan values

Warhaven · February 25, 2010, 9:21pm

StefanK:

Hi,

it’s right, 1 is an integer number, to test a boolean value you must coerce it
set foo to 1
if (foo as boolean) then
	display dialog "True!"
end if
Unlike other languages, where true means “not zero”, AppleScript distinguishes numeric and booelan values

Hmm. I suppose for a strongly typed language like AppleScript, it would make more sense to require implicit casting this way. I’m just so used to C and PHP, that it baffled me that it didn’t automatically consider non-zero as true.