how to use include c++ code example

Example 1: cpp #include "" <>

#include <iostream>  // Searches iostream in Standard C++ Header files but not in the Current file's folder
#include "myiostream.h" // Searcher myiostream.h in the Current file's folder and also the Standard Header files

Example 2: include cpp

#include <iostream>
#include "foop.h"

int main(int argc, char *argv[])
{
int x=42;
std::cout << x <<std::endl;
std::cout << foo(x) << std::endl;
return 0;
}