三目运算表达式为：条件？结果1：结果2
条件为真，返回结果1，条件为假，返回结果2.
goto:
eg：
cout << "1.xxxx" << endl;
cout << "2.xxxx" << endl;
goto Flag;
cout << "3.xxxx" << endl;
cout << "4.xxxx" << endl;
Flag;
cout << "5.xxxx" << endl;
------------->
1.xxxx
2.xxxx
5.xxxx
原文：https://www.cnblogs.com/kelin1122/p/15094783.html