第三节 运算符和条件判断语句
案例1:运算符
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//结果 int result; //算数运算符 Console.Write("请输入第一个数:"); int num1 = int.Parse(Console.ReadLine()); Console.Write("请输入第二个数:"); int num2 = int.Parse(Console.ReadLine()); //加(表达式) result = num1 + num2; Console.WriteLine("两个数的和是:{0}+{1}={2}", num1, num2, result); //减(表达式) result = num1 - num2; Console.WriteLine("两个数的差是:{0}-{1}={2}", num1, num2, result); //乘(表达式) result = num1 * num2; Console.WriteLine("两个数的乘是:{0}*{1}={2}", num1, num2, result); //除表达式) result = num1 / num2; Console.WriteLine("两个数的除是:{0}/{1}={2}", num1, num2, result); //取余 result = num1 % num2; Console.WriteLine("两个数的余数:{0}%{1}={2}", num1, num2, result); Console.ReadKey();
案例2:关系运算符
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bool result; //关系运算符 Console.Write("请输入第一个数:"); int num1 = int.Parse(Console.ReadLine()); Console.Write("请输入第二个数:"); int num2 = int.Parse(Console.ReadLine()); //==等于 result = num1 == num2; //Console.WriteLine("{0}=={1}:{2}", num1, num2, num1 == num2); Console.WriteLine("{0}=={1}:{2}", num1, num2, result);//: 冒号两个数比较 //> 大于 result = num1 > num2; //Console.WriteLine("{0}>{1}:{2}", num1, num2, num1> num2); Console.WriteLine("{0}>{1}:{2}", num1, num2, result); //<小于 result = num1 < num2; //Console.WriteLine("{0}<{1}:{2}", num1, num2, num1<num2); Console.WriteLine("{0}<{1}:{2}", num1, num2, result); //>=大于等于 result = num1 >= num2; //Console.WriteLine("{0}>={1}:{2}", num1, num2, num1>= num2); Console.WriteLine("{0}>={1}:{2}", num1, num2, result); //<=小于等于 result = num1 <= num2; //Console.WriteLine("{0}<={1}:{2}", num1, num2, num1<= num2); Console.WriteLine("{0}<={1}:{2}", num1, num2, result); //!=不等于 result = num1 != num2; //Console.WriteLine("{0}!={1}:{2}", num1, num2, num1!= num2); Console.WriteLine("{0}!={1}:{2}", num1, num2, result); Console.ReadKey();
案例3:逻辑运算符
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/// <summary> /// 逻辑运算符 /// </summary> /// <param name="args"></param> static void Main(string[] args) { int i = 10; int j = 15; int k = 20; int t = 7; // && :与(并且) 左右两边必须都满足 Console.WriteLine(i == j && k >= t); // ||:或 任意一个满足即可 Console.WriteLine(i == j || k >= t); // ! :非 bool b = false; Console.WriteLine(!b); Console.WriteLine(!(i == j)); Console.ReadKey();
案例4:自增自减运算符
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//自增(++),自减(--) int i = 10; // i++; i = i + 1; Console.WriteLine(i); //++在前先计算再赋值 Console.WriteLine(++i); //++在后先赋值后计算 Console.WriteLine(i++); int j = 10; //j--; j = j - 1; Console.WriteLine(j); //--在前先计算再赋值 Console.WriteLine(--j); //--在后先赋值后计算 Console.WriteLine(j--); Console.ReadKey();
案例5 :复合运算符
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//复合运算符 Console.Write("请输入第一个数:"); int num1 = int.Parse(Console.ReadLine()); Console.Write("请输入第二个数:"); int num2 = int.Parse(Console.ReadLine()); // num1 += num2;//num1=num1+num2 Console.WriteLine("{0}+={1}结果:{2}", num1, num2, (num1 += num2)); Console.WriteLine("{0}-={1}结果:{2}", num1, num2, (num1 -= num2)); Console.WriteLine("{0}*={1}结果:{2}", num1, num2, (num1 *= num2)); Console.WriteLine("{0}/={1}结果:{2}", num1, num2, (num1 /= num2)); Console.WriteLine("{0}%={1}结果:{2}", num1, num2, (num1 %= num2)); Console.ReadKey();
案例6:条件判断句 if
//if语句 Console.Write("请输入第一个数:"); int num1 = int.Parse(Console.ReadLine()); Console.Write("请输入第二个数:"); int num2 = int.Parse(Console.ReadLine()); if (num1 == num2) { Console.WriteLine("{0}和{1}相等", num1, num2); } Console.ReadKey(); //if....else Console.Write("请输入起床时间:"); int hour = int.Parse(Console.ReadLine()); if (hour <= 7 && hour >= 6) { Console.WriteLine("做公交车去"); } else { Console.WriteLine("要迟到了。。。。。。打的去"); } Console.ReadKey(); //if....else if... Console.Write("请输入起床时间:"); int hour = int.Parse(Console.ReadLine()); if (hour > 24 || hour < 0) { Console.WriteLine("你输入的时间不正确"); } else if (hour <= 7 && hour >= 6) { Console.WriteLine("做公交车去"); } else if (hour < 6 && hour > 0) { Console.WriteLine("继续睡觉。。。。。。。"); } else if (hour > 7 && hour < 9) { Console.WriteLine("要迟到了。。。。。。打的去"); } else { Console.WriteLine("不去了。。。。。旷工"); } Console.ReadKey(); //if.....嵌套 Console.Write("请输入起床时间:"); int hour = int.Parse(Console.ReadLine()); if (hour == 7) { Console.Write("昨天是否领过工资(1.领过 2.未领)"); int oper = int.Parse(Console.ReadLine()); if (oper == 1) { Console.WriteLine("牛排套餐!"); } else { Console.WriteLine("大瓶油条!"); } } else { Console.WriteLine("被领导批了....."); } Console.ReadKey()