list = [1, 2.3, 'four', false]
puts list
Results in
1
2.3
four
false
So far, so good.
s = "and the answer is: "
list.each {|item| s << item }
puts s
gives me
testltlt.rb:4:in `<<': failed to convert Float into String (TypeError)
testltlt.rb:4
testltlt.rb:4:in `each'
testltlt.rb:4
Why?
Brent