From: Robert Klemme <shortcutter@...>
Date: 2012-07-12T22:10:22+09:00
Subject: Re: how to check string is numeric or not

On Thu, Jul 12, 2012 at 12:16 PM, Lucky Nl <lists@ruby-forum.com> wrote:
> I want to check the value is numeric or not

According to your example you want to check whether a string
represents an integer value (floats are numeric, too).

> For example
> when i am checking numeric or not am expecting as below results
> "34" =>  true
> 34 => true
> "34sdfds" => it should return false
> 34.90 =>  false

You can use Integer() to do that:

Ruby version 1.8.7
irb(main):001:0> %w{34 34sdfds 34.90}.each do |s| printf "%p: %p\n",
s, (Integer(s) rescue false) end
"34": 34
"34sdfds": false
"34.90": false
=> ["34", "34sdfds", "34.90"]

But actually you do not need a separate check, just use Integer to
convert the string to a Fixnum / Bignum and deal with the exception.

Kind regards

robert


-- 
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