case使用例子

case使用例子

1. #include <iostream>
2. using namespace std;
4. int main()
5. {
6. char choice;
7. cout << "Enter A, B, or C: ";
8. cin >> choice;
9. switch (choice)
10. {
11. case 'A' :
12. cout<< "You entered A. \n";
13. case 'B' :
14. cout << "You entered B. \n";
15. case 'C' :
16. cout << "You entered C.\n";
17. default:
18. cout << "You did not enter A, B, or C!\n";
19. }
20. return 0;
21. }

程序运行结果：

Enter A, B, or C: A
You entered A.
You entered B.
You entered C.
You did not enter A, B, or C!

在没有 break 语句之后，此程序“渎职”放行了匹配 case 表达式下面的所有语句，使它们都被执行了，但有时这样的效果也正是程序员想要的，如下面所示：

纯文本复制

1. #include <iostream>
2. using namespace std;
4. int main()
5. {
6.     char feedGrade;
7.     //Get the desired grade of feed
8.     cout << "Our dog food is availablein three grades:\n";
9.     cout << "A, B, and C. Which do you want pricing for? ";
10.     cin >> feedGrade;
11.     // Find and display the price
12.     switch(feedGrade)
13.     {
14.      case 'a':
15.       case 'A':
16.        cout << "30 cents per pound.\n";
17.         break;
18.       case 'b':
19.       case 'B':
20.        cout << "30 cents per pound.\n";
21.         break;
22.       case 'c':
23.       case 'C':
24.         cout << "15 cents per pound.\n";
25.         break;
26.       default :
27.         cout << "That is an invalid choice.\n";
28.     }
29.     return 0;
30. }

程序输出结果：

Our dog food is available in three grades:
A, B, and C. Which do you want pricing for? b
20 cents per pound.

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标签：case,cout,feedGrade,choice,break,例子,使用,entered
来源： https://www.cnblogs.com/feng100/p/14964710.html