表达式必须为可修改的左值。

Question

typedef int MHF;typedef struct LNode{ char quming[20]; char zuozhe[20]; char geshou[20]; MHF nian; MHF yue; MHF ri; struct LNode *next;}LNode, *LinkList;int listinsert(LinkList &L, int i, char *quming, char *zuozhe, char *geshou, MHF &nian, MHF &yue, MHF &ri){ if (i < 1) return 0; int j = 0; LinkList p = L,s; while ((j < i - 1) && p != NULL) { p = p->next; j++; } if (p == NULL) return 0; else { s = new LNode; if (s == NULL) { cout << "结点分配失败\n"; return 0; } s->quming = quming; cout << quming << endl; cout << s->quming << endl; s->geshou = geshou; cout << geshou << endl; cout << s->geshou << endl; s->zuozhe = zuozhe; cout << zuozhe << endl; cout << s->zuozhe << endl; s->nian = nian; s->yue = yue; s->ri = ri; s->next = p->next; p->next = s; return 1; }}s报错，说表达式必须为可修改的左值，这是为什么？？？

Answer 1

就是说你表达式里面的左边的必须是变量，不能是常量
eg:int n=2;//赋值表达式n=2的左值为变量n，合法
    2=2非法