Safe integer parsing in Ruby?

Question

I have a string, say `'123'`, and I want to convert it to `123`.I know you can simply do `some_string.to_i`, but that converts `'lolipops'` to `0`, which is not the effect I have in mind. I want it to blow up in my face when I try to convert something invalid, with a nice and painful `Exception`. Otherwise, I can't distinguish between a valid `0` and something that just isn't a number at all.**EDIT:** I was looking for the standard way of doing it, without regex trickery.

Answer 1

Here's one way:

num = nil

until num

puts "Enter an integer below:"

begin

num = Integer(gets.strip)

rescue

puts "Invalid number"

end

end

puts "You entered #{num}"