OpenEuphoria

RE: if statement not working

• Posted by bensler at mail.com Mar 21, 2002
• 457 views

Andy Serpa wrote:
> 
> xxmyt at yahoo.com wrote:
> > hello everyone. 
> > 
> > the code i pasted down works properly. however, it doesnt work in the 
> > second way.
> > 
> > my code:
> > include dos32lib.e
> > without warning
> > 
> > constant
> >     Win     = create( Window, "PASSWORD REQUIRED", 0, Default, Default, 
> > 400, 200, 0 ),
> > 
> >     Sle1    = create( EditText, "", Win, 10, 40, 120, 20, 0 ),
> >     Button1 = create( PushButton, "OK", Win, 180, 40, 120, 20, 0 )
> > 
> > 
> > procedure onClick_Button1()
> > 
> >      if  equal(getText(Sle1),"YES") then
> >          closeWindow(Win)
> >      end if
> > 
> > end procedure
> > 
> > onClick[Button1] = routine_id("onClick_Button1")
> > 
> > WinMain( Win )
> > 
> >   but if i change the if statement this way, i get an error message:
> > 
> >      if  getText(Sle1) = "YES" then
> >          closeWindow(Win)
> >      end if
> > 
> > error message says, the result of the if statemnt should be an atom. 
> > 
> > so whats it all about?
> > 
> 
> It means to compare sequences, and therefore any string, you have to use 
> 
> the "equal" or "compare" statements, not = < > !=.
> 
> Using the latter operators on a sequence is for expressions, and 
> compares each element of a sequence to its counterpart in another 
> sequence of equal length.  For instance,
> 
> s = {8,9,10} = {8,4,10}
> 
> Now s is {1,0,1}.
> 
> This facility is very useful, but can make if statements involving 
> sequences a bit non-intuitive.  Anyway, you gotta use equal & compare..
> 

Could you give an example of how that might be useful?
I understand the concept, but I can't wrap my brain around how I could 
use it.

btw:
That assignment statement is easier to understand if written:
  s = ({8,9,10} = {8,4,10})

Chris