do i have to add #include<iostream> using namespace std after every {} block

Question

i know these are dumb questions sorry

Answer 1

just include it once at the top of ur file
#include <iostream>
using namespace std;

//All ur code here

Answer 2

no. you only have to (and should) include files once.

There is actually two lines of code in your question. each line performs a seperate function.

#include<iostream>

#include 'includes' the file specfied in < file > or " file.h" so basically the file gets typed in front of what you write.

and then there is

using namespace std;

Using namespaces allows you to reference functions within the namespace without qualifiers.

name spaces are a good way to seperate your code but yeah. google namespaces c++.

Answer 3

Not really , there are also file specifics such as #include <string>.