C++ Nested switch Statements

C++ Decision Making

You can place aswitchas an externalswitchpart of the statement sequence, i.e., can be in aswitchUse another within a statementswitchstatement. Even if the case constants of the inner and outer switch contain common values, there is no contradiction.

The switch statement in C++ allows at least 256 nesting levels.

Syntax

In C++Nested switchSyntax of the statement:

switch(ch1) {
   case 'A': 
      cout << "这个 A 是外部 switch 的一部分";
      switch(ch2) {
         case 'A':
            cout << "这个 A 是内部 switch 的一部分";
            break;
         case 'B': // 内部 B case 代码
      }
      break;
   case 'B': // 外部 B case 代码
}

Example

Example

#include <iostream>
using namespace std;
 
int main ()
{
   // Local variable declaration
   int a = 100;
   int b = 200;
 
   switch(a) {
      case 100:
         cout << "This is part of the outer switch" << endl;
         switch(b) {
            case 200:
               cout << "This is part of the inner switch" << endl;
         }
   }
   cout << "The exact value of a is " << a << endl;
   cout << "The exact value of b is " << b << endl;
 
   return 0;
}

When the above code is compiled and executed, it produces the following result:

这是外部 switch 的一部分
这是内部 switch 的一部分
a 的准确值是 100
b 的准确值是 200

C++ Decision Making

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