Check if a string contains only digits in ruby

Question

I have a string which is passed as a parameter to a function. Here, I want to check if the string contains only numbers. So I had a check like below:

def check_string(string)
  result = false
  if string.to_i.to_s.eql? string
    result =  true
  end
  result
end

But the problem arises when a string starts with 0. In that case, a false is returned.

check_string('123')  #=> true
check_string('0123') #=> false

How can I solve this issue?

Answer 1

You can try the following

def check_string(string)
  string.scan(/\D/).empty?
end

It would be truthy if string contains only digits or if it is an empty string. Otherwise returns false.