Objective-C嵌套switch语句

可以将switch作为外部switch语句序列的一部分。 即使内部和外部switch的case常量包含公共值，也不会产生冲突。

语法

嵌套switch语句的语法如下 -

switch(ch1) {
   case 'A': 
      printf("This A is part of outer switch" );

      switch(ch2) {
         case 'A':
            printf("This A is part of inner switch" );
            break;
         case 'B': /* case code */
      }
      break;
   case 'B': /* case code */
}

示例代码

#import <Foundation/Foundation.h>

int main () {

   /* 局部变量定义 */
   int a = 100;
   int b = 200;

   switch(a) {
      case 100: 
         NSLog(@"This is part of outer switch\n", a );
         switch(b) {
            case 200:
               NSLog(@"This is part of inner switch\n", a );
         }
   }
   NSLog(@"Exact value of a is : %d\n", a );
   NSLog(@"Exact value of b is : %d\n", b );

   return 0;
}

执行上面示例代码，得到以下结果：

2018-11-15 00:55:06.093 main[167622] This is part of outer switch
2018-11-15 00:55:06.095 main[167622] This is part of inner switch
2018-11-15 00:55:06.095 main[167622] Exact value of a is : 100
2018-11-15 00:55:06.095 main[167622] Exact value of b is : 200