这是一个用于计算的菜单驱动程序。
#include <iostream>
#include <cmath>
using namespace std;
void Choices();
int x;
int n;
float fact;
float cosh(float x, int n);
float sinh(float x, int n);
float factorial( int n );
int main ()
{ char exit;
char choice;
bool option1hasrun = false;
while (exit != 'y' || exit != 'Y')
{
Choices();
cin >> choice;
if (choice == '1' && option1hasrun == false) {
cout << "Please give a value for x: ";
cin >> x;
cout << "Please give a value for the approximation order n: ";
cin >> n;
cout << endl;
option1hasrun = true;
}
else if (choice == '2' && option1hasrun == true)
{
cout << "The hyperbolic sinh of x is: " << sinh(x) << endl;
cout << "Using Taylor series is it: " << sinh(x, n) << endl;
}
else if (choice == '3' && option1hasrun == true)
{
cout << "The hyperbolic cosh of x is: " << cosh(x) << endl;
cout << "Using Taylor series is it: " << cosh(x, n) << endl;
}
else if (choice == '4' && option1hasrun == true)
{
cout << "old value of x = " << x << endl;
cout << "old approximation = " << n << endl;
cout<< "Please give new value of x: " ;
cin >> x;
cout << endl;
cout << "Please give new n: " ;
cout << endl;
cin >> n;
}
if ((choice=='2' || choice=='3' || choice=='4') && option1hasrun==false)
{
cout << "You have to enter a value first!\n\n";
}
if (choice<'0' || choice > '4')
{
cout << "Wrong choice. Only options 1-4 are available.\n\n";
}
else if (choice == '0' && option1hasrun==true)
{
cout << "Are you sure you want to quit? (Y/N) ";
cin >> exit;
if (exit =='y' || exit == 'Y') {
cout << "bye bye!!";
}
}
/*输入Y后我想让程序停止,但是目前还在继续循环*/ }
return 0;
}
float factorial( int n )
{
float fact = 1;
for ( int i = 1; i <= n; i++ )
{
fact = fact * i;
}
return fact;
}
float sinh(float x, int n)
{
float sum = 0;
for ( int i = 0; i <= n; i++ )
{
sum = sum + pow(x, 2*i +1)/factorial(2*i +1);
}
return sum;
}
float cosh(float x, int n)
{
float sum = 0;
for ( int i = 0; i <= n; i++ )
{
sum = sum + pow(x, 2*i)/factorial(2*i);
}
return sum;
}
void Choices ()
{
cout << "MAIN MENU" << endl;
cout << "1. To enter the data. " << endl;
cout << "2. To calculate and approximate the sinh(x)" << endl;
cout << "3. To calculate and approximate the cosh(x) " << endl;
cout << "4. To modify data. " << endl;
cout << "0. to quit." << endl << endl;
cout << "Please make a choice :";
}
谁能帮我弄清楚为什么程序在选择 0 后继续循环?
最佳答案
输入的字符不能同时为'y'和'Y'。 尝试将退出条件更改为:
while (exit != 'y' && exit != 'Y')
关于c++ - 到达选项 0 时,如何停止循环返回菜单,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/23901178/