我怎样才能在没有向量的情况下改进这个 C++ 程序？

Question

**Guidelines:**get 3 seperate lists of data(array) for head of household, annual income, and household members, then get all annual incomes and average them together. Display in a neat table.

This is from a school project I wasn't allowed to use anything very advanced but I'd like to go back and improve it now. I'd like ti make it cleaner and particularly like to find more that I can take away from it than add to it.

// <Program Name> Programming Project #3 Average Income (Using Functions and Arrays)
// <Author> Brendan Jackson
// <Date of Programs Release> 08/05/15
// <Program Description> takes 3 arrays and displays them with average income
#include <iostream> // allows cin and cout statements
#include <iomanip> //allows setprecision
#include <string> //allows strings
using namespace std; // Namespace std allows program to use entities from <iostream>

int input(string[], int[], double[]); //function 1
double calculate_average_income(double[], int);  //function 2
void display_survey_data(string[], int[], double[],int , double);  //function 3


int main() // main function
{

    //variables for functions
    string name[10];

    int members[10];

    double income[10];

    int count_of_households;

    double average;

    //get input
    count_of_households = input(name, members, income);

    //calculate average
    average = calculate_average_income(income, count_of_households);


    //output all data in table
    display_survey_data(name, members, income, count_of_households, average);


    return 0;

}


int input(string name[], int members[], double income[]) //function 1
{

    // get household info
    int count_of_households = 0;

    cout << "How many house holds were there? ";
    cin >> count_of_households;
    //TODO: handle bad input (characters and decimals)
    if (count_of_households >= 11 || count_of_households < 0) 
    {
        cout << "must enter valid # " ; //TODO: more description
        count_of_households = 0; //set back to safe value
    }
    else 
    {

           //cycle through arrays                  
        for (int count = 0; count < count_of_households; count++) //TODO:  take out (count + 1) start from 1 alternatively
        {

            // get survey info for names
            cout << "Enter household #" << (count + 1) << "'s head of household name\t"  ;
            cin.ignore() ; // ignores keyboard buffer characters
            getline (cin, name[count]) ; 


            // get survey info for income
            cout << "Enter household #" << (count + 1) << "'s annual income\t"  ;
            cin >>  income[count];


            // get survey info for members
            cout << "Enter household #" << (count + 1) << "'s household members\t"  ;   
            cin >>  members[count]; 
        }   
    }
    return count_of_households;
}

double calculate_average_income(double income[], int count_of_households) //function 2
{


    //add incomes together
    double total = 0.0;
    double average = 0.0;

    //loop over income
    for (int count = 0 ; count < count_of_households; count++)
    {
        //add income to runnning total
        total += income[count];  
    }

    // save calculations
    average = total / count_of_households; 
    return average;
}




void display_survey_data(string name[], int members[], double income[],int count_of_households, double average) //funtion 3
{
    //print out header
    cout << setw(30) << ""
         << setw(30) << ""
         << setw(30) << "NUMBER OF\n" ;
    cout << setw(30) << "HOUSEHOLD NAME"
         << setw(30) << "ANNUAL INCOME"
         << setw(30) << "HOUSEHOLD MEMBERS\n" ;
    cout << setw(30) << "--------------------" 
         << setw(30) << "---------------" 
         << setw(30) << "------------------------\n" ;      
    ///loop over values
    for (int count = 0 ; count < count_of_households; count++)
    {
        cout << setw(30) << name[count]
             << setw(30) << setprecision(2) << fixed << showpoint << income[count]
             << setw(30) << members[count] 
             << endl;   
    }   
    // display average
    cout << endl
         << setw(30) << "AVERAGE INCOME"
         << setw(30) << average
         << endl;
}

Answer 1

You could use std::array

This is simply an array on the stack, just like you used, but has iterators, type safe, bound safe, use value semantics and work with most stl algorithm.

It is declared like this:

array<string, 3> myArray;

And it must be passed by reference, because passing by value will copy it's content:

void doSomething(array<int, 6>& aArray) {
    // do something
}

Notice that you must specify the length of the array, since it's a template parameter. If you want to have an array of any size, use tempaltes:

template<size_t length>
void foobar(array<double, length> theArray) {
    // do something else
}