C范围问题

Question

以下代码是否有效

int main(){
int * a = 0;
if ( !a ) {
    int b[500];
    a = b;
}

//do something with a, 
//has the array a is 
//pointing too gone out
//of scope and garbage
//or is it still fine?
}

Answer 1

不,不是,b已超出范围,访问它(通过指针)是未定义的行为.