Ruby dynamic symbol in each block

Question

How can I make my symbol dynamic with an incremental number like this:

@order.products.each do |product,num|
    = f.input :aanbod+num.to_s

Answer 1

This form is equivalent to "aanbod#{num}".to_sym and more concise:

= f.input :"aanbod#{num}"

Answer 2

= f.input ("aanbod" + num.to_s).to_sym

or

= f.input "aanbod#{num}".to_sym