I think instead of #include<iostream> ,it should be #include<iostream.h> ??

Answer 1

<iostream.h> is an old standard header file
that is obsolete in today's C++ compilers.
<iostream> is now the new standard for today's C++ compilers. Just like <cstring>
is used instead of <string.h> and
<cstdio> replaces <stdio.h> and <cctype>
replaces <ctype.h>.
Unless you are using a older compiler ,
it is best to always choose <iostream> over the older standard <iostream.h>. You can't
go wrong with that logic.

Answer 2

The C++ standard obsoleted <iostream.h> infavor of <iostream>. There is no guarantee the former is available and it certainly will not have been updated.

Answer 3

thankyou very much for your help 😊

Answer 4

iostream.h is c language writing style，in c++ we usually lost .h，every head file is.