c++ - 关于我的变量范围需要一些解释

Question

/* simple class that has a vector of ints within it */
class A
{
public:
   vector<int> int_list;
};

/* some function that just returns an int, defined elsewhere */
int foo();

/* I want to fill the object's int_list up */
A a_obj;

int main() {
   for (int i = 0; i < 10; i++) {
      int num = foo();
      a_obj.int_list.push_back( num );
   }
}

num 的范围是否仅限于 for 循环？退出for循环后会被销毁吗？如果我尝试访问 a_obj 的 int_list 中的数字，我将无法访问，因为其中的数字将被破坏吗？

Answer 1

Is the scope of num limited to the for loop?

是

Will it be destroyed once the for loop is exited?

它会在每次迭代后销毁，然后为下一次重新创建!

If I try to access the numbers in a_obj's int_list will I not be able to as the numbers inside will have been destroyed?

容器存储拷贝，因此您不必担心这一点。

你只会遇到引用和指针的这类问题。