如何在C++中实现字符输入验证

Question

我需要创建一个程序来计算正在构建的表的价格。

main((函数应该调用以下函数：

1. 一个接受标准中与桌子配套的椅子数量的函数。

2. 接受标准表面积(m2(的函数。

3. 接受标准中用于制作桌椅的木材类型的功能；"m代表桃花心木，o代表橡木，p代表松木。理想情况下，任何其他条目都应被拒绝。

4. 一个函数，使用椅子的数量(N(、桌子的表面积(S(和木材的类型(x(来计算价格。桌子的价格是x(S+1/2N(，其中松木、橡木和桃花心木的x分别为50美元、100美元和150美元。

5. 显示购买详细信息的功能。

目前的结果：

目前，我的代码只计算带有"m"(mahomgony(的桌子的价格，而不计算其他两种材料的价格。例如：

Number of chairs: 5
Surface area of table (m2): 5
Wood type: m
Total = 1125

如果我将木材类型更改为"o"或"p"，则会得到相同的价格

代码：

#include <iostream>
using namespace std;
int main(){
int N;
cout << "Number of chairs: ";
cin >> N;
int S;
cout << "Surface area (in meters squared) of the table: ";
cin >> S;
cout << "Type of wood ('m' = mahogony, 'o' = oak, 'p' = pine): ";
char x;
cin >> x;
while(x != 'm' && x != 'o' && x != 'p'){
cout << "Error. Invalid input. Please try again" << endl;
cout << "Type of wood ('m' = mahogony, 'o' = oak, 'p' = pine): ";
cin >> x;
}
int total;
if(x = 'm'){
total = 150*(S + (0.5*N));
} else if(x = 'o'){
total = 100*(S + (0.5*N));
} else if(x = 'p'){
total = 50*(S + (0.5*N));
}
cout << "--------------------n";
cout << "Details of purchase:n";
cout << "--------------------n";
cout << "Number of chairs: " << N << endl;
cout << "Surface area of table (m2): " << S << endl;
cout << "Wood type: " << x << endl;
cout << "Total = " << total << endl;
return 0;
}

Answer 1

#include <iostream>
using namespace std;
int main(){
int N;
cout << "Number of chairs: ";
cin >> N;
int S;
cout << "Surface area (in meters squared) of the table: ";
cin >> S;
cout << "Type of wood ('m' = mahogony, 'o' = oak, 'p' = pine): ";
char x;
cin >> x;
while(x != 'm' && x != 'o' && x != 'p'){
cout << "Error. Invalid input. Please try again" << endl;
cout << "Type of wood ('m' = mahogony, 'o' = oak, 'p' = pine): ";
cin >> x;
}
int total;
if(x == 'm'){
total = 150*(S + (0.5*N));
} else if(x == 'o'){
total = 100*(S + (0.5*N));
} else if(x == 'p'){
total = 50*(S + (0.5*N));
}
cout << "--------------------n";
cout << "Details of purchase:n";
cout << "--------------------n";
cout << "Number of chairs: " << N << endl;
cout << "Surface area of table (m2): " << S << endl;
cout << "Wood type: " << x << endl;
cout << "Total = " << total << endl;
return 0;
}

您必须==检查条件，==指定值

Answer 2

#include <iostream>
using namespace std;
int main(){
float N;
cout << "Number of chairs: ";
cin >> N;
float S;
cout << "Surface area (in meters squared) of the table: ";
cin >> S;
cout << "Type of wood ('m' = mahogony, 'o' = oak, 'p' = pine): ";
char x;
cin >> x;
while(x != 'm' && x != 'o' && x != 'p'){
cout << "Error. Invalid input. Please try again" << endl;
cout << "Type of wood ('m' = mahogony, 'o' = oak, 'p' = pine): ";
cin >> x;
}
float total=0.f;
if(x == 'm'){
total = 150.f*(S + (0.5f*N));
} else if(x == 'o'){
total = 100.f*(S + (0.5f*N));
} else if(x == 'p'){
total = 50.f*(S + (0.5f*N));
}
cout << "--------------------n";
cout << "Details of purchase:n";
cout << "--------------------n";
cout << "Number of chairs: " << N << endl;
cout << "Surface area of table (m2): " << S << endl;
cout << "Wood type: " << x << endl;
cout << "Total = " << total << endl;
return 0;
}