cout(打印)

cout 示例代码
//打印字符串
cout<<"Hello World!";

//打印变量
cout<<a;

//打印多条内容
cout<<"one"<<"two"<<a;

//打印完换行
//方法一:
cout<<"line 1."<<endl;
//方法二:
cout<<"line 2."<<"\n";
//方法三:
cout<<"line 3.\n";