C++ Primer Plus

Using Enumerators as Labels

Listing 6.11 illustrates using enum to define a set of related constants and then using the constants in a switch statement. In general, cin doesn’t recognize enumerated types (it can’t know how you will define them), so the program reads the choice as an int. When the switch statement compares the int value to an enumerator case label, it promotes the enumerator to int. Also the enumerators are promoted to type int in the while loop test condition.

Listing 6.11. enum.cpp

// enum.cpp -- using enum#include <iostream>// create named constants for 0 - 6enum {red, orange, yellow, green, blue, violet, indigo};int main(){    using namespace std;    cout << "Enter color code (0-6): ";    int code;    cin >> code;    while ...