加减乘除计算器——C primer plus 5edith chapter 8

来源：互联网发布：windows下重启nginx 编辑：程序博客网时间：2024/06/11 18:47

编写一个程序，显示一个菜单，为您提供加法、减法、乘法或除法的选项，获得您的选择后，该程序请求两个数，然后执行您选择的操作，该程序应该只接受它所提供的菜单选项，它应该使用float类型的数，并且如果用户未能输入数字应允许其重新输入，在除法的情况中，如果用户输入0作为第二个数，该程序应该提示用户输入一个新的值。

#include <stdio h="">#include <stdlib h="">#include <ctype h="">void operation_menu();char get_first();float get_float();char get_choice();int main(void){float num1, num2;char ch;printf_s("Enter the operation of your choice:\n");operation_menu();while ((ch=get_choice())!='q'){printf_s("Enter first number:");num1 = get_float();printf_s("Enter second number:");num2 = get_float();while (ch == 'd'&&num2 == 0){printf_s("!Please enter another number that does't include 0.\n");num2 = get_float();}switch (ch){case 'a':printf_s("%.2f+%.2f=%.2f\n", num1, num2, (num1 + num2));break;case 's':printf_s("%.2f-%.2f=%.2f\n", num1, num2, (num1 - num2));break;case 'm':printf_s("%.2f*%.2f=%.2f\n", num1, num2, (num1*num2));break;case 'd':printf_s("%.2f/%.2f=%.2f\n", num1, num2, (num1 / num2));break;default:break;}printf_s("Enter the operation of your choice:\n");operation_menu();}printf_s("Bye.\n");system("pause");return 0;}//获取第一个字符char get_first(){int ch;ch = getchar();while (isspace(ch)){ch = getchar();}while (getchar()!='\n'){continue;}return ch;}//打印菜单选项void operation_menu(){printf_s("a.add               s.subtract\n");printf_s("m.multiply          d.divide\n");printf_s("q.quit\n");}//获取数字float get_float(){float num;char str[40];while (scanf_s("%f",&num)!=1){gets_s(str);printf_s("%s is not a number.\n",str);printf_s("Please enter a number,such as 2.5,-1.78E8,or 3:");}while (getchar()!='\n'){;}return num;}//选择函数char get_choice(){char choice;choice = get_first();while (choice!='a'&&choice!='s'&&choice!='m'&&choice!='d'&&choice!='q'){printf_s("Please response with a,s,m,d or q.\n");choice = get_first();}return choice;}</ctype></stdlib></stdio>

0 0