From: Farrel Lifson <farrel.lifson@...>
Date: 2007-06-04T22:48:23+09:00
Subject: Re: How to check if a string is a integer ?

On 04/06/07, w wg <duzuike@gmail.com> wrote:
> How to check if a string is a integer ?

You can use either the String#to_i or Kernel#Integer methods

irb(main):001:0> "1234".to_i
=> 1234
irb(main):002:0> "123A".to_i
=> 123
irb(main):003:0> "A123".to_i
=> 0
irb(main):004:0> Integer("A1234")
ArgumentError: invalid value for Integer: "A1234"
        from (irb):4:in `Integer'
        from (irb):4
irb(main):005:0> Integer("1234A")
ArgumentError: invalid value for Integer: "1234A"
        from (irb):5:in `Integer'
        from (irb):5
irb(main):006:0> Integer("1234")
=> 1234
irb(main):007:0>

Farrel