1 // 30-逻辑表达式(逻辑运算符).cpp: 定义控制台应用程序的入口点。 2 // 3 4 #include "stdafx.h" 5 #include <iostream> 6 #include <climits> 7 #include <array> 8 #include <math.h> 9 #include <string> 10 using namespace std; 11 12 int main() 13 { 14 // || 或 15 int vip = 1; 16 if (vip == 1 || vip == 2) 17 { 18 cout << "获得优惠"; 19 } 20 21 bool res1 = true || false; 22 bool res2 = false || true; 23 bool res3 = false || false; 24 bool res4 = true || true; 25 cout << res1 << " "<<res2 << " "<<res3 << " "<<res4 << endl;//1 1 0 1 26 27 //&& 与 28 int age = 20; 29 if (age >= 18 && age <= 30) 30 { 31 cout << "你是青年" << endl; 32 } 33 34 bool res5 = 4 == 4 && 3 == 3; //只有两边同时为true时才为true,其他的都是false 35 bool res6 = 8 == 8 && 6 == 3; 36 bool res7 = 5 > 4 && 3 > 9; 37 bool res8 = 4 > 8 && 5 < 10; 38 bool res9 = 3 < 9 && 2 > 9; 39 cout << res1 << " " << res2 << " " << res3 << " " << res4 << " " << res5 << endl;//1 1 0 1 1 40 41 //! 取反 42 cout << !true << endl; //0 43 cout << !(10 > 9) << endl;//0 44 45 //?: 条件运算符、 46 //表达式1 ? 表达式2 : 表达式3 ; 当表达式1结果为true时,执行表达式2,当表达式1结果为false时,执行表达式3. 47 int i = true ? 100 : 90; 48 cout << i << endl; 49 50 int vvip = 1; 51 string res = vvip == 1 ? "有优惠" : "正常价格"; 52 cout << res << endl; //返回 有优惠 53 54 int vvvip = 1; 55 vvvip == 1 ? cout<<"有优惠" : cout << "正常价格"; //除了接语句外还可以接表达式 56 57 int t; 58 cin >> t; 59 return 0; 60 }