Wrong stringsizes printing. Why?

Question

If you input cat, dog and rat into code,
Stringsize output for cat and dog is 4, but for rat is 3

Why?

Code:
https://code.sololearn.com/caeYtyr8q9qS/?ref=app

Thanks for advance

Answer 1

you can see here in second paragraph http://www.cplusplus.com/reference/cstdio/fgets/

`A newline character makes fgets stop reading, but it is considered a valid character by the function and included in the string copied to str.`
you can prove it by check their last character and see if its \n or not

Answer 2

Thank you good sir!