int x = 5;    goto JUMP;    printf("x is : %d\n",x);JUMP:    int a = 0;  <=== 错误，lable后面不能申明变量，只能是表达式语句(statement)，哪怕是空语句..    printf("%d",a);

 

int x = 5;    goto JUMP;    printf("x is : %d\n",x);JUMP: ;     /// 空语句，正确    int a = 0;     // 前面有空语句，正确    printf("%d",a);

 

label只在函数内有效