Question

String#to_i returns 0 when the string does not match any number characters, and I understand that many people including myself consider this unnatural and would rather expect nil to be returned in such case. But Matz designed it otherwise. What is the best way to distinguish strings that actually are "0" (or "00", etc.) from strings that do not include number characters?

Answer 1

Use:

Integer('')                         # =>  #<ArgumentError: invalid value for Integer: ""> 
Integer('0')                       # => 0