1.2节练习

1.3

#include<iostream>int main() {    std::cout << "Hello,World." << std::endl;    return 0;}

1.4

#include<iostream>int main() {    std::cout << "输入相乘的两个因数：" << std::endl;    int v1 = 0, v2 = 0;    std::cin >> v1 >> v2;    std::cout << "两数乘积为" << v1*v2 << std::endl;    return 0;}

1.5

#include<iostream>int main() {    std::cout << "输入相乘的两个因数：" << std::endl;    int v1 = 0, v2 = 0;    std::cin >> v1 >> v2;    std::cout << "两数乘积为";    std::cout << v1*v2;    std::cout << std::endl;    return 0;}

1.6

#include<iostream>int main() {    int v1 = 0, v2 = 0;    std::cin >> v1 >> v2;    std::cout << "The sum of" << v1;    << "and" << v2;    << "is" << v1 + v2 << std::endl;    return 0;}

这段程序不合法，
<< “and” << v2;
<< “is” << v1 + v2 << std::endl;
这两句前面已经有；了 ，说明std：：cout已经结束了，那么下面两句就没有意义了。
修改：去除前面的2个；即可

#include<iostream>int main() {    int v1 = 0, v2 = 0;    std::cin >> v1 >> v2;    std::cout << "The sum of" << v1    << "and" << v2    << "is" << v1 + v2 << std::endl;    return 0;}