Why we use #include<iostream.h> in case of #include<iostream>

Answer 1

Please read: https://www.sololearn.com/Discuss/288609/?ref=app

Answer 2

You shouldn't use it like that. The correct way to use STL headers is without. h. The same is true if you want to include C headers. Just use <cstdio> instead of <stdio.h> and iostream instead of iostream.h