hi thanks
forgive me i ask here
does there is a Difference between #include"isosream" and #include<iostream> there is no difference i use "" or <> in my all #includes?
example:#include<conio.h> #include"conio.h" ?
and there is no difference between cout <<120; and cout <<"120"; ?
if i want print \n not create new line how can i do that ? i mean print \n in monitor screen
what is difference between getch() and _getch() ?

That explained in chapter 2. Sorry, i'm cant give you page number because English and Russian version of this book have different numeration.
It something like if you want to use standart headers,use <>, because then compiler will search headers in folder which contain standart headers only.
If you want to use your own headers, then need to use "" because at first it will search in folder with source code,next in folder which standart headers. I'm prefer to use double quotes, because it work for sure.
How about to use std::cout<< "\\n SomeText";?
You receive on your screen something like this:\n SomeText