Return two and more values from a method

Question

Is there any possibility to return multiple values from method? Something like this:

def someMethod()   return ["a", 10, SomeObject.new] end  [a, b, c] = someMethod 

Answer 1

def sumdiff(x, y)   return x+y, x-y end #=> nil  sumdiff(3, 4) #=> [7, -1]  a = sumdiff(3,4) #=> [7, -1] a #=> [7, -1]  a,b=sumdiff(3,4) #=> [7, -1] a #=> 7 b #=> -1  a,b,c=sumdiff(3,4) #=> [7, -1] a #=> 7 b #=> -1 c #=> nil 

Answer 2

Ruby has a limited form of destructuring bind:

ary = [1, 2, 3, 4] a, b, c = ary p a # => 1 p b # => 2 p c # => 3  a, b, *c = ary p c # => [3, 4]  a, b, c, d, e = ary p d # => 4 p e # => nil 

It also has a limited form of structuring bind:

 a = 1, 2, 3  p a # => [1, 2, 3] 

You can combine those two forms like so:

a, b = b, a # Nice way to swap two variables  a, b = 1, 2, 3 p b # => 2  def foo; return 1, 2 end a, b = foo p a # => 1 p b # => 2 

There's several other things you can do with destructuring / structuring bind. I didn't show using the splat operator (*) on the right hand side. I didn't show nesting (using parantheses). I didn't show that you can use destructuring bind in the parameter list of a block or method.

Here's just an appetizer:

def foo(((a, b, c, d), e, *f), g, *h)   local_variables.sort.each do |lvar| puts "#{lvar} => #{eval(lvar).inspect}" end end  foo([[1, 2, 3], 4, 5, 6], 7, 8, 9) # a => 1 # b => 2 # c => 3 # d => nil # e => 4 # f => [5, 6] # g => 7 # h => [8, 9]