Comment by Peter - Reinstate Monica on How can I validate that an user enter a value (int) instead of skip with the enter key

Note that this is the expected behavior though. It makes a lot of sense to skip all whitespace -- for example, imagine your program reads actually from a file; then this leniency imposes fewer restrictions on the specific file layout. All values can be in one line, or each on their own. It wouldn't matter provided the data is all there, in the right order.