c++语句switch语句

The error: case label not within a switch statement occurs in C language with switch case statement, when switch (variable/value) statement is terminated by the semicolon ( ; ).

错误： 当switch(变量/值)语句由分号( ; )终止时，C语言中的 case标签 使用switch case语句以C语言出现。

Example:

#include <stdio.h>
int main(void) {
	int choice = 2;
	switch(choice);
	    case 1:
	        printf("Case 1\n");
	        break;
	    case 2:
	        printf("Case 2\n");
	        break;	    
	    case 3:
	        printf("Case 3\n");
	        break;	    
	    case 4:
	        printf("Case 4\n");
	        break;	    
	    default:
	        printf("Case default\n");
	return 0;
 
Output
 
 
prog.c: In function ‘main’:
prog.c:9:6: error: case label not within a switch statement
      case 1:
prog.c:11:10: error: break statement not within loop or switch
          break;
          ^~~~~
prog.c:12:6: error: case label not within a switch statement
      case 2:
prog.c:14:10: error: break statement not within loop or switch
          break;
          ^~~~~
prog.c:15:6: error: case label not within a switch statement
      case 3:
prog.c:17:10: error: break statement not within loop or switch
          break;
          ^~~~~
prog.c:18:6: error: case label not within a switch statement
      case 4:
prog.c:20:10: error: break statement not within loop or switch
          break;
          ^~~~~
prog.c:21:6: error: ‘default’ label not within a switch statement
      default:
      ^~~~~~~
 
How to fix?
 
 
See the statement switch(choice); it is terminated by semicolon (;) – it must not be terminated. To fix this error, remove semicolon after this statement.
 
 
 参见语句switch(choice); 它以分号( ; )终止–一定不能终止。 要解决此错误，请在此语句后删除分号。 
 
 
Correct code:
 
 
 正确的代码： 
 
 
#include <stdio.h>
int main(void) {
	int choice = 2;
	switch(choice)
	    case 1:
	        printf("Case 1\n");
	        break;
	    case 2:
	        printf("Case 2\n");
	        break;	    
	    case 3:
	        printf("Case 3\n");
	        break;	    
	    case 4:
	        printf("Case 4\n");
	        break;	    
	    default:
	        printf("Case default\n");
	return 0;
 
Output
 
 
Case 2
  
翻译自: https://www.includehelp.com/c-programs/case-label-not-within-a-switch-statement-error-in-c.aspx
 
 
c++语句switch语句
 
                    c++语句switch语句The error: case label not within a switch statement occurs in C language with switch case statement, when switch (variable/value) statement is terminated by the semicolon (;). 错误：当switch...
error: a label can only be part of a statement and a declaration is not a statement
switch(a){　　　　　　　　swtch(a){
case 1:　　　　　　　　　ca
                case 1: cout << "平局" << endl; break;
                case 2: cout << "你赢了" << endl; break;
                case 3: cout << "电脑赢了" << endl; break;
            break;
        case 2:
            switch(computer)
                case 1: cout << "电脑赢了" << endl; break;
                case 2: cout << "平局" << endl; break;
                case 3: cout << "你赢了" << endl; break;
            break;
        case 3:
            switch(computer)
                case 1: cout << "你赢了" << endl; break;
                case 2: cout << "电脑赢了" << endl; break;
                case 3: cout << "平局" << endl; break;
            break;
        default:
            cout << "输入错误！" << endl;
            break;
    return 0;
以上是一个简单的猜拳游戏实现，使用了嵌套的 switch 语句来处理不同的情况。
接下来，让我们看一下如何使用 C++ 的 switch 语句实现菜单程序。
```c++
#include <iostream>
using namespace std;
int main()
    int choice;
    cout << "请选择您要进行的操作：" << endl;
    cout << "1.添加新的记录" << endl;
    cout << "2.修改现有记录" << endl;
    cout << "3.删除现有记录" << endl;
    cout << "4.查看所有记录" << endl;
    cout << "5.退出程序" << endl;
    cin >> choice;
    switch(choice)
        case 1:
            cout << "您选择了添加新的记录。" << endl;
            break;
        case 2:
            cout << "您选择了修改现有记录。" << endl;
            break;
        case 3:
            cout << "您选择了删除现有记录。" << endl;
            break;
        case 4:
            cout << "您选择了查看所有记录。" << endl;
            break;
        case 5:
            cout << "您选择了退出程序。" << endl;
            break;
        default:
            cout << "输入错误，请重新选择。" << endl;
            break;
    return 0;
以上是一个简单的菜单程序实现，使用了 switch 语句来处理用户的不同选择。