> test = false and true => false > test => false > test = true and false #this is the point I don't understand! => false > test => true Why does ruby behave in this way and how would I use it correctly to not run into this problem?
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1 Answer
Precedence. test = true and false means this:
(test = true) and false not this:
test = (true and false) Use parentheses as above, or && instead of and, if you want the assignment to come last:
test = true && false 
2 Comments
theor
From the github ruby styleguide : 'The and and or keywords are banned. It's just not worth it. Always use && and || instead.'
Mark Reed
Inherited from Perl. In the beginning, there was only
&& and ||. But these were used both like C (as logical primtives) and like the shell (to handle success/failure). In the latter use the precedence caused surprises like my @info = stat($file) || die "error" calling stat in scalar instead of list context. The lower-precedence and/or/not were introduced to solve those headaches, but gave us new ones, and Ruby borrowed them right along with the rest of the stuff it got from Perl.