我想创建一个文件，我可以在其中将 Persons 添加到 PersonList 中，包括一个确保不超过 PersonList 容量的计数器。我评论了所有功能，以明确他们应该执行哪些任务。
在编译期间，我收到以下错误：
invalid use of non-static data member 'PersonList::m_Capacity'
不幸的是，我无法弄清楚代码中有什么问题：
主文件
#include <iostream>
#include "Person.h"
#include "PersonList.h"
int main()
{
Person p1 = Person("John", 21);
Person p2 = Person("Elham", 19);
PersonList p_list = PersonList();
p_list.add(p1);
p_list.add(p2);
std::cout << p_list.get_Size() << std::endl;
Person p = p_list.get(0);
std::cout << p.get_Name() << " " << p.get_Age() << std::endl;
return 0;
}
人.h
#ifndef PERSON_H
#define PERSON_H
class Person
{
public:
Person();
Person(std::string Name, int Age);
void set_Name(std::string name);
void set_Age(int age);
std::string get_Name();
int get_Age();
private:
std::string m_Name;
int m_Age;
};
#endif // PERSON_H
个人.cpp
#include <string>
#include "Person.h"
Person::Person(){}
Person::Person(std::string Name, int Age){
// pre: 0 <= Age
// post: m_Name, if pre Name (is true) Age = m_Age,
// otherwise age = -1
set_Name(Name);
if (0 <= Age){
set_Age(Age);
}
else{
set_Age(-1);
}
}
void Person::set_Name(std::string Name){
// post: m_Name = Name
m_Name = Name;
}
void Person::set_Age(int Age){
// pre: 0 <= Age
// post: if pre Age (is true) = m_Age, otherwise m_Age = -1;
if (0 <= Age){
m_Age = Age;
}
else set_Age(-1);
}
std::string Person::get_Name(){
// post: returns name
return m_Name;
}
int Person::get_Age(){
// post: returns age
return m_Age;
}
个人列表.h
#ifndef PERSONLIST_H
#define PERSONLIST_H
class PersonList
{
public:
PersonList();
void add(Person p);
void set_Size(int Size);
int get(int index);
int get_Size();
private:
const int m_Capacity;
const Person m_Empty;
Person m_Data[m_Capacity];
int m_Size;
};
#endif // PERSONLIST_H
个人列表.cpp
#include "Person.h"
#include "PersonList.h"
PersonList::PersonList()
m_Capacity(10), m_Empty(Person())
{
// post: has created a new PersonList-object with
// CAPACITY elements and size = 0
set_Size(0);
}
void PersonList::add(Person p){
// pre: size < CAPACITY
// post: if pre (is true) p has been stored at the
// first empty location. size was incremented.
if (m_Size < m_Capacity){
m_Data[m_Size] = p;
set_Size(m_Size+1);
}
}
void set_Size(int Size){
m_Size = Size;
}
int PersonList::get(int index){
// pre: 0 <= index && index < size
// post: if pre returns data[index] otherwise returns EMPTY
if (0 <= index && index < m_Size){
return m_Data[index];
}
else{
return m_EMPTY;
}
}
int PersonList::get_Size(){
// post returns size;
return m_Size;
}