Is there a ruby idiom for "If do-this," and "do-this" just as a simple command?
for example, I'm currently doing
object.method ? a.action : nil
to leave the else clause empty, but I feel like there's probably a more idiomatic way of doing this that doesn't involve having to specify a nil at the end. (and alternatively, I feel like taking up multiple lines of code would be wasteful in this case.
As a general rule: you pretty much never need the ternary operator in Ruby. The reason why you need it in C, is because in C if
is a statement, so if you want to return a value you have to use the ternary operator, which is an expression.
In Ruby, everything is an expression, there are no statements, which makes the ternary operator pretty much superfluous. You can always replace
cond ? then_branch : else_branch
with
if cond then then_branch else else_branch end
So, in your example:
object.method ? a.action : nil
is equivalent to
if object.method then a.action end
which as @Greg Campbell points out is in turn equivalent to the trailing if
modifier form
a.action if object.method
Also, since the boolean operators in Ruby not just return true
or false
, but the value of the last evaluated expression, you can use them for control flow. This is an idiom imported from Perl, and would look like this:
object.method and a.action