Question

> a = %w[foo1 foo2 foo3 foo4 foo5 foo6]
 => ["foo1", "foo2", "foo3", "foo4", "foo5", "foo6"] 


> a.each_with_index {|b,i| puts "b #{i}"; puts "== mod4 "  if i%4==0}
b 0
== mod4 
b 1
b 2
b 3
b 4
== mod4 
b 5

I have an array a . I want to iterate every element and puts something every 4 element.
However,
if i%4 == 0 is too ugly . Is there a beautiful to achieve this ?

Answer 1

What you are trying to do is quite unusual. What about boundary conditions?

Maybe you can use each_slice successfully?

a.each_slice(4) do |group|
  group.each{|i| p i}
  puts "== mod4"
end

# Prints:
"foo1"
"foo2"
"foo3"
"foo4"
== mod4
"foo5"
"foo6"
== mod4