case2:a++;b++;break;case3:a++;b++;少了空格,应为:case 2:a++;b++;break;case 3:a++;b++;
switct(1)-->case 1-->a++输出a=0;同理b=0
}case2:a++;b++;break;case3:a++;b++;}printf("a=%d,b=%d/n",a,b);}
0,0