[OOP]析构函数

DataStore.h

struct Student
{
    int id;
    char name[16];
    Student* next;
};

class DataStore
{
public:
    DataStore();
    ~DataStore();

public:
    void Add(const Student* data);
    Student* Find(int id);
    void Print();

private:
    Student m_head;
};

DataStore.cpp

#include <stdio.h>
#include <stdlib.h>
#include "DataStore.h"

DataStore::DataStore()
{
    m_head.next = NULL;
}

DataStore::~DataStore()
{
    Student* p = m_head.next;
    while(p)
    {
        Student* next = p->next;
        free(p);
        p = next;
    }
}


void DataStore::Add(const Student* data)
{
    // 创建对象、复制数据
    Student* copy = (Student*)malloc(sizeof(Student));
    *copy = *data;

    // 插入一个对象到链表中
    Student* cur = m_head.next; // 当前节点current
    Student* pre = &m_head;  // 上一个节点previous
    while(cur)
    {		
        if(copy->id < cur->id) // 找到这个位置
            break;

        pre = cur;
        cur = cur->next;  // 找到最后一个对象
    }

    // 插入到pre节点的后面
    copy->next = pre->next;
    pre->next = copy;
}

Student* DataStore::Find(int id)
{
    Student* p = m_head.next; 
    while(p)
    {
        if(p->id == id)
            return p;

        p = p->next; // 下一个对象
    }
    return NULL;
}

void DataStore::Print()
{
    Student* p = this->m_head.next; 
    while(p)
    {
        printf("ID: %d, name: %s\n", p->id, p->name);
        p = p->next; // 下一个对象
    }
}