# Numeric boolean check

**URL:** <https://www.ruby-forum.com/t/numeric-boolean-check/163073>\
**Category:** Ruby\
**Created:** [March 17, 2009, 5:46am UTC](https://www.ruby-forum.com/t/numeric-boolean-check/163073 "2009-03-17T05:46:03Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![leveille](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/a88e57/32.png) [@leveille](https://www.ruby-forum.com/u/leveille)\
**Post date:** [March 17, 2009, 5:46am UTC](https://www.ruby-forum.com/t/numeric-boolean-check/163073/1 "2009-03-17T05:46:03Z")

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Is there a way to check for numeric in Ruby similar to the way you can  
in Lisp?

(number? 5) =\> #t  
(number? -0.453) =\> #t  
(number? 'a) =\> #f

returns true for any numeric value and false for everything else.

This:  
Float(x) rescue false

almost works but doesn’t return true on numeric values

---

<div class="post-metadata">

**Author:** ![leveille](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/a88e57/32.png) [@leveille](https://www.ruby-forum.com/u/leveille)\
**Post date:** [March 17, 2009, 6:01am UTC](https://www.ruby-forum.com/t/numeric-boolean-check/163073/2 "2009-03-17T06:01:15Z")

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> Is there a way to check for numeric in Ruby similar to the way you can  
> in Lisp?
> 
> (number? 5) =\> #t  
> (number? -0.453) =\> #t  
> (number? 'a) =\> #f

irb(main):021:0\> (10/3.0).is\_a? Numeric  
=\> true  
irb(main):022:0\> (10/3).is\_a? Numeric  
=\> true  
irb(main):023:0\> “a”.is\_a? Numeric  
=\> false

## saji

–  
Saji N. Hameed

APEC Climate Center +82 51 668 7470  
National Pension Corporation Busan Building 12F  
Yeonsan 2-dong, Yeonje-gu, BUSAN 611705 removed\_email\_address@domain.invalid  
KOREA