How to check if a variable is a number or a string?

Question

How to check if a variable is a number or a string in Ruby?

Answer 1

The finishing_moves gem includes a String#numeric? method to accomplish this very task. The approach is the same as installero's answer, just packaged up.

"1.2".numeric?
#=> true

"1.2e34".numeric?
#=> true

"1.2.3".numeric?
#=> false

"a".numeric?
#=> false