Hello,

   I want to have some function that will two parameters. First is the
variable name and second is a value.
Inside I will check:
   * if the variable is existed I do nothing
   * else I assign "value" to variable

It should be something like this but it is not working.

def set_default(name, val)
    if ! name then
        eval "#{name} = #{val}"
    end
end

set_default("b", "2")
puts "b = " + b