c++ - 为什么我的指针会导致段错误？

Question

#include <iostream>
#include <stdio.h>
#include <string.h>
#include <vector>
using namespace std;
  struct student
  {
    char name[50];
    char lname[50];
    int id;
    float GPA;
  };
void toAdd(vector<student*> *plist);
void toDelete(vector<student*>* plist);
void toPrint(vector<student*>* plist);
int main(){
  vector<student*> list;
  vector<student*>* plist = &list;
  char input[80];
  bool running = true;
  while (running == true){
    cout << "What would you like to do?" << endl;
    cin.getline (input,80);
    if(strcmp (input, "ADD") == 0){
      toAdd(plist);
    }
    else if(strcmp (input, "DELETE") == 0){
    }
    else if(strcmp (input, "PRINT") == 0){
    }
    else{
      cout << "That is not a valid response!" << endl;
        }
  }
}

void toAdd(vector<student*> *plist){
  student* stu;
  cout << "What a test!" << endl;
  cout << "First Name: ";
  cin.getline(stu->name,20);
  cout << "Last Name: ";
  cin.getline(stu->lname,20);
  cout << "ID: ";
  cin.getline(stu->id);
  cout << "GPA: ";
  cin.getline(stu->GPA);
  plist->push_back(stu);
}
void toDelete(){

}
void toPrint(){
}

我不明白我做错了什么。我已经研究这段代码好几个小时了，真的需要一些帮助。当我运行代码并尝试输入名称时，出现错误“Segmentation Fault(core dumped)”。我觉得这可能真的很简单，但是没有一个在线解释对我有帮助。 :(

Answer 1

您取消引用一个未初始化的指针。在你打电话之前

cin.getline(stu->name,20);

你需要先使用new分配它的内存

student* stu = new student;