From: Jason Creighton <androflux@...>
Date: 2003-09-04T11:04:33+09:00
Subject: Re: Possible to make compound if statements...

On Wed, 3 Sep 2003 12:54:04 +0900
Kurt Euler <keuler@portal.com> wrote:

> All-
> 
> Is it possible to make compound if statements in Ruby, something like:
> 
> if field[0] == "AIX" or if field[2] =~ /ldap/
> 	puts "BLAH"
> end
> 
> (but different, of course, since the above doesn't work.)

Wrong syntax, use 'or'

if field[0] == "AIZ" or field[2] =~ /ldap
  puts "BLAH"
end

Now here's the interesting bit: The syntax you used was almost valid!
Look here:

~/prog/ruby$ cat weird-if.rb 
a,b,c = 1,2,3

if a == 1 and if b == 2
    puts "b == 2"
    c > 3
  end
  puts "BLAH!"
end

puts "Different way of saying the same thing:"
    
if a == 1 and (if b == 2 then puts "b == 2"; c > 3; end)
  puts "BLAH!"
end
~/prog/ruby$ ruby weird-if.rb 
b == 2
Different way of saying the same thing:
b == 2
~/prog/ruby$

So that construct is the same as:

if true and false
  puts "BLAH!"
end

where:

true: a == 1
false: The result of evaling the 'if' statement is the last expression
evalulated, that is, c > 3

So obviously, "BLAH!" isn't printed.

Jason Creighton