weak typing - Does ruby 1.9.2 have an is_a? function?

Question

I googled that there is an is_a? function to check whether an object is an integer or not.

But I tried in rails console, and it doesn't work.

I ran the code like the following:

 "1".is_a?
 1.is_a?

Did I miss something?

Answer 1

You forgot to include the class you were testing against:

"1".is_a?(Integer) # false
1.is_a?(Integer) # true