为什么L* creat(int a)函数中有无return p都可以？

Question

//创造链表+尾插+遍历
#include"1.h"

typedef struct node {
int num;
node* next;
}L;
L* creat(int a);
void wei(L* head, L* newass);
void bl(L* head);
void main()
{
L* head = creat(0);
for (int i = 1; i < 10; i++)
{
wei(head, creat(i));
}
bl(head);

}
L* creat(int a)
{
L* p;
p = (L*)malloc(sizeof(L));
if (p == NULL)
{
cout << "wrong" << endl;
exit(0);
}
memset(p, 0, sizeof(L));
p->num = a;
p->next = NULL;
//return p;
}
void wei(L* head, L* newass)
{
L* p = head;
while (NULL != p->next)
{
p = p->next;
}
p->next = newass;
}
void bl(L* head)
{
L* p = head;
while (NULL != p->next)
{
cout << p->num << endl;
p = p->next;

}
cout << p->num << endl;

}

Answer 1

必须要有return p;
否则程序是错的。错的程序未必一定结果和拟预期不同。好比闯红灯是错的，不等于说闯红灯一定会出事故。