我正在研究一个项目，我坚持认为是范围和逻辑问题。我正在创建一个名为“Person”的类，它有四个字符串变量，姓氏，名字，喜欢的颜色和性别。我正在创建一个名为'PersonList'的第二个类，其中一个变量是'Person'对象的数组。我设置了一个名为MAX的const int来确定数组的大小（目前为3）。最后，我想将一个'Person'对象的字符串变量输入到main中声明的'newDude'对象中。例如，当'readNewPerson'函数运行时，我输入Doe，John，Blue，Male。这一步工作!!
接下来，我希望将这个'newDude'复制到在地址dudesList [0]和'readNewPerson'函数中声明的'dudesList'对象中再次运行。如果一切正常，我认为Smith，Jane，Pink，Female应该被复制到dudesList [1]和Johnson，Mike，Green，Male应该被复制到dudesList [2]。最后，我想将所有三个对象打印到控制台。
我在'addPersonToList'和'printList'函数中的'for'循环中某处出错，我的变量没有正确迭代。我的猜测是，因为我在函数内部声明了计数器'i'，所以每次创建'newDude'时它都会死并重置为零。如果我对此是正确的，那么宣布计数器的最佳位置在哪里以及何时应该迭代它？
我非常感谢任何人可能提供的任何反馈，我当然不希望任何人为我做任务。我现在可以在正确的方向上使用一点点推动，因为我对这应该是一项非常简单的任务感到非常沮丧，至少在概念上是这样。
到目前为止，这是我的计划：
// contact list with one-word strings only
#include <iostream>
using namespace std;
const int MAX = 3;
class Person
{
private:
string dudesLName;
string dudesFName;
string dudesColor;
string dudesGender;
public:
void readNewPerson (); // function declaration to ask for info
void printPerson (); //function declaration to display info to console
};
class PersonList
{
private:
Person dudesList [MAX];
public:
void addPersonToList (Person newDude); //function declaration to add my newDude to the dudesList array
void printList (); //function declaration to print the entire array
};
//the main function is a simple switch-case asking for user choices
int main (void)
{
Person newDude; //one object contains 4 simple string variables
PersonList List; //one object contains an array of [MAX] dudes
int userChoice; //integer for the user's choice in switch-case
cout << "~~Welcome to Stephen's Contact List~~" << endl;
cout << "Please enter your choice:" << endl;
cout << " 1 - enter " << MAX << " new people" << endl;
cout << " 2 - print the contact list" << endl;
cout << " 3 - retrieve by last name" << endl;
cout << " 4 - retrieve by address" << endl;
cout << " 5 - retrieve by gender" << endl;
cin >> userChoice;
switch (userChoice)
{
case 1:
for (int i = 0; i < MAX; i++)
{
newDude.readNewPerson (); //function call to enter one person's info
List.addPersonToList (newDude); //function call to add newDude to dudesList array
}
break;
case 2:
cout << "2 doesn't work yet" << endl;
List.printList (); //function call to print entire list
break;
case 3:
cout << "3 doesn't work yet" << endl;
break;
case 4:
cout << "4 doesn't work yet" << endl;
break;
case 5:
cout << "5 doesn't work yet" << endl;
break;
}
cout << "thanks dude!!" << endl;
return 0;
}
// function definitions
void Person::readNewPerson ()
{
cout << "enter a dude's last name please" << endl;
cin >> dudesLName;
cout << "enter a dude's first name please" << endl;
cin >> dudesFName;
cout << "enter a dude's favorite color please" << endl;
cout << "for test purposes, just enter one word" << endl;
cin >> dudesColor;
cout << "enter a dude's gender please" << endl;
cout << "male or female is fine, so is dude or dudette" << endl;
cin >> dudesGender;
return;
}
void Person::printPerson ()
{
cout << "dude's name is " << dudesLName << ", " << dudesFName << endl;
cout << "his (her?) favorite color is: " << endl;
cout << dudesColor << endl;
cout << "and his (her?) gender is: " << endl;
cout << dudesGender << endl << endl;
return;
}
void PersonList::addPersonToList (Person newDude)
{
for (int i = 0; i < MAX; i++) //supposed to iterate the array address as it adds Person objects to the array
dudesList [i] = newDude; //this is where the newDude object is copied to the array
return;
}
void PersonList::printList()
{
for (int i = 0; i < MAX; i++)
dudesList [i].printPerson ();
return;
}
答案 0 :(得分：1)
好吧，似乎出了什么问题，就是你要将同一个人添加到列表中3次。当你致电addPersonToList
void PersonList::addPersonToList (Person newDude)
{
for (int i = 0; i < MAX; i++) //supposed to iterate the array address as it adds Person objects to the array
dudesList [i] = newDude; //this is where the newDude object is copied to the array
return;
}
现在你有几个选择。
最简单的做法和最简单的方法是将索引传递给你调用它的方法，并使你的方法如下：
void PersonList::addPersonToList (Person newDude, int index)
{
dudesList [index] = newDude; //this is where the newDude object is copied to the array
}
然后在你的switch语句中，像这样调用它
case 1:
for (int i = 0; i < MAX; i++)
{
newDude.readNewPerson (); //function call to enter one person's info
List.addPersonToList (newDude, i); //function call to add newDude to dudesList array
}
现在可能是“正确”的方法，就是跟踪你在PersonList类中添加的最后一个索引
class PersonList
{
private:
Person dudesList [MAX];
int indexToAdd = 0; // your new index
public:
void addPersonToList (Person newDude); //function declaration to add my newDude to the dudesList array
void printList (); //function declaration to print the entire array
};
然后在addPersonToList方法
void PersonList :: addPersonToList（Person newDude） { for（int i = 0; i＆lt; MAX; i ++）//应该迭代数组地址，因为它将Person对象添加到数组中 dudesList [indexToAdd] = newDude; //这是将newDude对象复制到数组的位置 indexToAdd ++; 返回; }