ruby idiom a ||= b means?

[Ratnavel P S]

What does the ruby idiom a ||= b mean?

Thanks,
Ratnavel

 

[Rob Biedenharn]

What does the ruby idiom a ||= b mean?

Thanks,
Ratnavel

It is like:
a || a = b
See David A. Black's Blog
http://dablog.rubypal.com/2008/3/25/a-short-circuit-edge-case

-Rob

P.S. Please don't ask the same question on both Rails and Ruby lists/
forums.

Rob Biedenharn http://agileconsultingllc.com
(e-mail address removed)

 

[Lars Christensen]

It is like:
        a || a = b

In english, thats: If a is nil or false, then leave it, else assign a
= b.

Often used instead of code like this:

if a.nil? then
a = b
end

 

[Dave Bass]

What does the ruby idiom a ||= b mean?

It's commonly used to assign default values to things.
This idiom is also very common in Perl, which is presumably where it
came from.

 

[Ruby Freak]

This has been discussed nearly to death at:
http://groups.google.com/group/comp...80e285aff?lnk=gst&q=Or+equal#bf7f73380e285aff