Comments on: Ruby boolean operator (or ruby parsing) bug http://adamloving.com/internet-programming/ruby-boolean-operator-or-ruby-parsing-bug Seattle Social Web Development Thu, 06 May 2010 12:25:40 +0000 http://wordpress.org/?v=2.9.1 hourly 1 By: Aaron http://adamloving.com/internet-programming/ruby-boolean-operator-or-ruby-parsing-bug/comment-page-1#comment-199 Aaron Thu, 10 Jul 2008 14:53:49 +0000 http://adamloving.com/?p=399#comment-199 This isn't a bug. The operator 'or' is below the operator '=' in the order of operations, and the operator '||' is above '='. (This is documented in the section 'Operator Expressions' here http://docs.huihoo.com/ruby/ruby-man-1.4/syntax.html.) So Ruby parses your first assertion as x = (false || true), and does just what you want. But it parses your second one as (z = false) or true, which means it assigns z to the value of false, and then returns the value true. If you change your second statement to 'z = (false or true)', it should work. Personally, I just avoid that 'or' operator in favor of the '||' operator, because I don't want to deal with stuff like this. This isn’t a bug. The operator ‘or’ is below the operator ‘=’ in the order of operations, and the operator ‘||’ is above ‘=’. (This is documented in the section ‘Operator Expressions’ here http://docs.huihoo.com/ruby/ruby-man-1.4/syntax.html.)

So Ruby parses your first assertion as x = (false || true), and does just what you want. But it parses your second one as (z = false) or true, which means it assigns z to the value of false, and then returns the value true.

If you change your second statement to ‘z = (false or true)’, it should work. Personally, I just avoid that ‘or’ operator in favor of the ‘||’ operator, because I don’t want to deal with stuff like this.

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