如何在C++中使用枚举类型？

Question

我不明白如何使用枚举类型.我明白它们是什么,但我不太明白它们的目的.

我制作了一个输入三角形三边的程序,输出它们是等腰,斜角或等边.我想在某个地方加入枚举类型,但是不知道在哪里以及如何使用它们.任何帮助,将不胜感激.

#include <iostream>

using namespace std;

enum triangleType {scalene, isosceles, equilateral, noTriangle};

triangleType triangleShape(double x, double y, double z);
void printTriangleShape(triangleType shape);

int main()
{
    double x, y, z;
    triangleType scalene, isosceles, equilateral, noTriangle;

    cout << "Please enter the three sides of a triangle:" << endl;
    cout << "Enter side 1: ";
    cin >> x;
    cout << endl;
    cout << "Enter side 2: ";
    cin >> y;
    cout << endl;
    cout << "Enter side 3: ";
    cin >> z;
    cout << endl;

    triangleType t = triangleShape(x, y, z); 
printTriangleShape(t);

    return 0;
}

triangleType triangleShape(double x, double y, double z)
{
   triangleType scalene, isoceles, equilateral, noTriangle;
    if (((x+y) > z) && ((x+z) > y) && ((y+z) > x))
    {
        cout << "You have a triangle!" << endl;
            if (x == y && y == z)
               return equilateral;
            else if (x == y || x == z || y == z)
                 return isosceles;
            else
               return scalene;
    }
    else if ((x+y) <= z || ((x+z) <= y) || ((y+z) <= x))
        return noTriangle;  
} 
void printTriangleShape(triangleType shape)
{
    switch (shape)
    {
    case scalene: cout << "Your triangle is Scalene!" << endl;
        break;
    case isosceles: cout << "Your triangle is an isosceles!" << endl;
        break;
    case equilateral: cout << "Your triangle is an equilateral!" << endl;
        break;

    }
}

Answer 1

这是一个值,您可能希望从函数中返回它.

尝试:

triangleType triangleShape(double x, double y, double z) {
  if (...) {
    return scalene;
  } else if (...) {
    return isosceles.
  } else if (...) {
    return equilateral
  } else {
    return noTriangle;
  } 
}

注意,您可以打印结果,但它将打印为整数: scalene = 0, isosceles = 1, ...

编辑,打印您可能想要这样做:

void printTriangleShape(triangleType shape) {
   switch (shape) {
     case scalene:
       cout << "Your triangle is Scalene!" << endl;
       break;
     case isosceles:
       cout << "Your triangle is isosceles!" << endl;
       break;
     ...;
   }
}