Today at App Academy my pair and I were asked to explain the meaning of Ruby’s “double pipe equals” operator to our cohorts. I figured that might be a good topic to post here.
The double pipe equals, which will be referred to as “||=” from now on, is an operator that’s used for conditional assignment.
In a nutshell the||= operator’s usage is something like this:
blah ||= blabbity_blah()
This essentially says: “if blah is false then set it to blabbity_blah(), otherwise leave it set to whatever it was before we started”
Here’s a contrived, but-still-real-code, example lifted (and modified) from Wikibooks: