[Q] class and case

[E.-R. Bruecklmeier]

Hi,

a = 3

#A
case a
when Fixnum
p "Fixnum"
end

#B
case a.class
when Fixnum
p "Fixnum"
end


why ist #A working while #B isn't?

Thanks!

Eric.

 

[Austin Ziegler]

Hi,

a = 3

#A
case a
when Fixnum
p "Fixnum"
end

#B
case a.class
when Fixnum
p "Fixnum"
end

why ist #A working while #B isn't?

% ri "Module.==="
------------------------------------------------------------- Module#===
mod === obj => true or false
------------------------------------------------------------------------
Case Equality---Returns +true+ if _anObject_ is an instance of
_mod_ or one of _mod_'s descendents. Of limited use for modules,
but can be used in +case+ statements to classify objects by class.

Thus:

case a.class
when Fixnum
p "Fixnum" # => Never Reached
when Class
p "Class!" # => or Object, or Module, or several others, see
a.class.ancestors
end

-austin

 

[E.-R. Bruecklmeier]

Austin Ziegler schrieb:

% ri "Module.==="
------------------------------------------------------------- Module#===
mod === obj => true or false

Thanks a lot!

Eric.

 

[Gavin Sinclair]

Hi,

a = 3

#A
case a
when Fixnum
p "Fixnum"
end

#B
case a.class
when Fixnum
p "Fixnum"
end

why ist #A working while #B isn't?

Because #A and #B are not the same!

Gavin