c++ lesson 一（命名空间输入输出）

//
//  main.cpp
//  C++lessonOne
//
//  Created by keyan on 15/11/13.
//  Copyright © 2015年 keyan. All rights reserved.
//

#include <iostream>
#include <cmath>
int main(int argc, const char * argv[]) {
// insert code here...

using namespace std;
cout <<"Come up and C++ me some time";
cout <<endl;

int carrots;
cin >> carrots;
carrots = carrots + 2;
cout << "You won.t regret it!"
<<endl;

cout<<"Carrots"<<carrots<<"haha"<<endl;
std::cout << "Hello, World!\n";

using namespace std;
double area;
cout<<"kaishi";
cin>>area;
double side;
side = sqrt(area);
cout<<"That the equivalent of a square"<<side
<<"feet to side"<<endl;
cout<<"How fascinating"<<endl;

return 0;
}