如何使用if语句包装代码块，这意味着有红宝石的方法吗？

Question

I have a block like this:

Blah.where(....).each do |b|
  # Code here
end

I only want to run this if some_var is not nil or empty. Is there a ruby way to do this other than:

if !some_var.nil
  Blah.where(....).each do |b|
    # Code here
  end
end

Answer 1

First of all you might want

unless some_var.nil?

instead.

ALSO you can use an end if at the end of the block

Answer 2

Blah.where(....).each do |b|
  #...
end if some_var

Answer 3

You could look into the AndAnd gem for some inspiration on solving problems with nil. For an overview check out my answer here .

Other then that the probably best way is to do

Blah.where(...).each do |a|
   ...
end unless some_var.nil?