I have a program that should create a sorted linked list by name. However, after running it, the output gives me an error:
Undefined symbols for architecture x86_64:
"StudentList::insertNode(Student)", referenced from:
buildList(StudentList&) in main-acc0ea.o
"StudentList::StudentList()", referenced from:
_main in main-acc0ea.o
"StudentList::~StudentList()", referenced from:
_main in main-acc0ea.o
"StudentList::displayList(double) const", referenced from:
_main in main-acc0ea.o
"StudentList::displayList(double, double) const", referenced from:
_main in main-acc0ea.o
"StudentList::displayList() const", referenced from:
_main in main-acc0ea.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
My code:
File Main.cpp
#include <iostream>
#include "StudentList.h"
using namespace std;
void buildList(StudentList &);
int main()
{
// Define a StudentList object
StudentList list;
buildList(list); // Insert data into the list
list.displayList();
double gpa;
cout << "Enter a gpa: ";
cin >> gpa;
list.displayList(gpa);
double from, to;
cout << "Enter a gpa range: ";
cin >> from >> to;
list.displayList(from, to);
system("pause");
return 0;
}
void buildList(StudentList &list)
{
// Define and initialize an array of Student objects
Student s[10] =
{ { 2.3, "Tom" }, { 2.5, "John" }, { 3.1, "Paul" }, { 3.9, "Linda" }, { 3.6, "Bob" }, { 2.7, "Ann" }, { 4.0, "Mary" },
{ 3.2, "Andy" }, { 0, "#" } };
//Insert data from array into the linked list
for (int i = 0; s[i].name != "#"; i++)
{
list.insertNode(s[i]);
}
}
File StudentList.h
#ifndef STUDENTLIST_H
#define STUDENTLIST_H
#include<string>
struct Student
{
double gpa;
std::string name;
};
class StudentList
{
private:
// Declare a structure for the list
struct ListNode
{
Student stu; // The value in this node
ListNode *next; // To point to the next node
};
ListNode *head; // List head pointer
int count; // To keep track of the number of nodes in the list
public:
StudentList(); // Constructor
~StudentList(); // Destructor
// Linked list operations
int getCount() const { return count; }
void insertNode(Student);
void displayList() const;
void displayList(double) const;
void displayList(double,double) const;
/* Write your code here */
};
#endif
File StudentList.cpp
#include <iostream> // For cout and NULL
#include "StudentList.h"
using namespace std;
//**************************************************
// Constructor
// This function allocates and initializes a sentinel node
// A sentinel (or dummy) node is an extra node added before the first data record.
// This convention simplifies and accelerates some list-manipulation algorithms,
// by making sure that all links can be safely dereferenced and that every list
// (even one that contains no data elements) always has a "first" node.
//**************************************************
StudentList::StudentList()
{
head = new ListNode; // head points to the sentinel node
head->stu.gpa = -1;
head->stu.name = "";
head->next = NULL;
count = 0;
}
//**************************************************
// displayList shows the value
// stored in each node of the linked list
// pointed to by head.
//**************************************************
void StudentList::displayList() const
{
ListNode *pCur; // To move through the list
// Position pCur: skip the head of the list.
pCur = head->next;
// While pCur points to a node, traverse the list.
cout << endl;
while (pCur)
{
// Display the value in this node.
cout << pCur->stu.gpa << " " << pCur->stu.name << endl;
// Move to the next node.
pCur = pCur->next;
}
cout << endl;
}
//**************************************************
// The insertNode function inserts a node with
// stu copied to its value member.
//**************************************************
void StudentList::insertNode(Student dataIn)
{
ListNode *newNode; // A new node
ListNode *pCur; // To traverse the list
ListNode *pPre; // The previous node
// Allocate a new node and store num there.
newNode = new ListNode;
newNode->stu = dataIn;
// Initialize pointers
pPre = head;
pCur = head->next;
// Find location: skip all nodes whose gpa is less than dataIn's gpa
while (pCur != NULL && pCur->stu.name < dataIn.name)
{
pPre = pCur;
pCur = pCur->next;
}
// Insert the new node between pPre and pCur
pPre->next = newNode;
newNode->next = pCur;
// Update the counter
count++;
}
//**************************************************
// Destructor *
// This function deletes every node in the list. *
//**************************************************
StudentList::~StudentList()
{
}
void StudentList::displayList(double aboveGPA) const
{
ListNode *pCur; // To move through the list
// Position pCur: skip the head of the list.
pCur = head->next;
// While pCur points to a node, traverse the list.
cout << endl;
while (pCur)
{
if (pCur->stu.gpa >= aboveGPA)
{
// Display the value in this node.
cout << pCur->stu.gpa << " " << pCur->stu.name << endl;
}
// Move to the next node.
pCur = pCur->next;
}
cout << endl;
}
void StudentList::displayList(double gpa1, double gpa2) const
{
ListNode *pCur; // To move through the list
// Position pCur: skip the head of the list.
double upperLimit, loweLimit;
if (gpa1 > gpa2)
{
upperLimit = gpa1;
loweLimit = gpa2;
}
else
{
upperLimit = gpa2;
loweLimit = gpa1;
}
pCur = head->next;
// While pCur points to a node, traverse the list.
cout << endl;
while (pCur)
{
if (pCur->stu.gpa >= loweLimit && pCur->stu.gpa<=upperLimit)
{
// Display the value in this node.
cout << pCur->stu.gpa << " " << pCur->stu.name << endl;
}
// Move to the next node.
pCur = pCur->next;
}
cout << endl;
}
I don't know if my code is wrong or if it's this problem:
Visual Studio Code clang error: linker command failed with exit code 1 on Mac
I tried adding "${fileDirname}/*.cpp" in my task JSON file, but it's still giving me the same error. Is there another solution for this error?
