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
