I have a variable assigned to user input. I want to check if the user input is an integer. how do I do that?
a = gets
Asked
Active
Viewed 56 times
-2
-
More or less the same [here](https://stackoverflow.com/questions/50668704/checking-if-an-answer-is-empty-or-not) – iGian Jun 03 '18 at 20:25
-
Possible duplicate of https://stackoverflow.com/q/5661466/5345794 – Guillaume Jun 03 '18 at 20:55
-
`gets` returns a `String`, so `a` will *never* reference an `Integer`, it will *always* be a `String`. – Jörg W Mittag Jun 03 '18 at 21:36
-
What Jörg said. Also maybe this: https://stackoverflow.com/q/1235863/125816 – Sergio Tulentsev Jun 03 '18 at 21:40
-
You can use this trick: ```a = Integer(gets) rescue 'should be integer'``` – Oleksandr Holubenko Jun 04 '18 at 07:09
1 Answers
3
There is no need to check: gets returns a String, so a will never reference an Integer, it will always be a String. There is no possible way that a will ever reference an Integer in the code you posted.
Jörg W Mittag
- 363,080
- 75
- 446
- 653
-
I think, *never* is a bit too strong. The method may have been redefined, or the context is executed inside a class where `gets` doesn't necessarily return a `String`.... – user1934428 Jun 04 '18 at 04:56
-
@user1934428: "in the code you posted". In that code, "never" is the correct estimation. – Sergio Tulentsev Jun 04 '18 at 18:29
-
1@SergioTulentsev : Right you are. From the way the OP wrote it, we must assume that this statement is not just a line picked from a large application, and in this case, *never* is indeed correct. I didn't consider that this might just be the first line of a complete application. Thanks for having me corrected. – user1934428 Jun 05 '18 at 05:43