From: "David A. Black" <dblack@...>
Date: 2007-10-26T01:56:04+09:00
Subject: Re: Change a string to an integer, report an error if the string does not represent an integer?

Hi --

On Fri, 26 Oct 2007, Randy Kramer wrote:

> Can anybody point me to a way to check if a string represents a valid integer
> and then convert it to an integer?
>
> It is very likely the string will contain leading zeros, and should not
> contain any trailing non-numeric characters.
>
> Per the documentation (pickaxe 2), to_i won't quite do it, it will just ignore
> trailing non-numeric characters.

There's a method called Integer (uppercase I and all). It blows up if
the string has extra stuff:

irb(main):001:0> Integer("0003")
=> 3
irb(main):002:0> Integer("0003a")
ArgumentError: invalid value for Integer: "0003a"


David

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