Question

所以，现在，我可以从sumtwonums.cpp文件运行我的代码，但是当我尝试从main运行它时，我遇到了很多错误。我已经把这个代码磨了很长时间，我似乎无法得到它。（我是c ++的初学者，所以我知道我的代码可以大大改进。）无论如何，这是我尝试从总和运行它时得到的错误。

In function 'main':
16 C:\Users\jozef\Desktop\SYDE 2017\SYDE 121 LABS\Lab702\sum.cpp    undefined reference to `input(SumTwoNums&)
17 C:\Users\jozef\Desktop\SYDE 2017\SYDE 121 LABS\Lab702\sum.cpp    undefined reference to `input(SumTwoNums&)
18 C:\Users\jozef\Desktop\SYDE 2017\SYDE 121 LABS\Lab702\sum.cpp    undefined reference to `print(SumTwoNums&)'
19 C:\Users\jozef\Desktop\SYDE 2017\SYDE 121 LABS\Lab702\sum.cpp    undefined reference to `print(SumTwoNums&)'
20 C:\Users\jozef\Desktop\SYDE 2017\SYDE 121 LABS\Lab702\sum.cpp    undefined reference to `sum(SumTwoNums&, SumTwoNums&, int*)'
21  C:\Users\jozef\Desktop\SYDE 2017\SYDE 121 LABS\Lab702\sum.cpp   undefined reference to `print(int*)'

sumtwonums.cpp显示如下：

#include <iostream>
#ifndef SUMTWONUMS_H
#define SUMTWONUMS_H

const int LENGTH = 20;

struct SumTwoNums{
    public:
        int array[LENGTH];
        char c_array[LENGTH];
};
void input(SumTwoNums &s);
void sum(SumTwoNums &s1, SumTwoNums &s2, int s[]);
void print (SumTwoNums &s);
void print (int a[]);
#endif 

#include "sumtwonums.h"

using namespace std;


void sum(SumTwoNums &s1, SumTwoNums &s2, int s[]){
    for (int i = LENGTH-1; i >= 0; i--){
        if (s1.array[i] + s2.array[i] + s [i] > 9 && i != LENGTH-1){
            s [i] += (s1.array[i] + s2.array[i] - 10);
            s [i-1] += 1;
        }else if (s1.array[i] + s2.array[i] + s [i]<= 9 && i != LENGTH-1){
            s [i] += s1.array[i] + s2.array[i];
        }else if (i == LENGTH-1 && s1.array[i] + s2.array[i] + s [i]> 9 ){
            s[i] += s1.array[i] + s2.array[i];
            s[i-1] += 1;
        }else if (i == LENGTH-1 && s1.array[i] + s2.array[i] + s [i] <= 9 ){
            s[i] += s1.array[i] + s2.array[i];
        }else if (i == LENGTH-1 && s1.array[i] + s2.array[i] + s [i] > 9){///////
            s [i] += (s1.array[i] + s2.array[i]);                         ////Check To see if overflow
            cout << "There is an overflow" << endl;                       ///////
        }
    }
}
void input(SumTwoNums &s){
    int dig = 0;
    for (int i = 0; i < LENGTH; i++){
        s.array[i] = 0;
    }
    cout << "Please enter a number:\n";
char next;
int x = LENGTH-1;
cin.get(next);
while (next != '\n' && next != 'E' && x >= 0){  
    dig++;   
    s.c_array[x] = next;
    cin.get(next);
    x--;
}
for (int i = 1; i <= LENGTH; i++){
    if (dig != 0) {
        s.array[LENGTH - dig] = s.c_array[LENGTH - i] - '0';
        dig--;
        }
    }   
}

void print (SumTwoNums &s){
    int count = 2;
    for (int i = 0; i <  LENGTH ; i++){
        if (s.array[i] != 0 || ( s.array[i - 1] != 0 && s.array[i] == 0 && s.array[i + 1] != 0)){
                cout << s.array[i];
            if (count%3==0 && count != 0 && i != LENGTH-1){
                cout << ",";
            }
        }
        count++;
}
cout << endl;
}
void print (int a[]){
    int count = 2;
    for (int i = 0; i <  LENGTH ; i++){
        if (a[i] != 0 || ( a[i - 1] != 0 && a[i] == 0 && a[i + 1] != 0)){
                cout << a[i];
            if (count%3==0 && count != 0 && i != LENGTH-1){
                cout << ",";
            }
        }
        count++;
}
cout << endl;
}

sum.cpp显示如下：

#include <iostream>
#include "sumtwonums.h"
using namespace std;

int main() {
    SumTwoNums num1;
    SumTwoNums num2;
    int total [LENGTH];
    int rtotal [LENGTH];
    for (int i = 0; i < 20; i ++){
        total[i] = 0;
        rtotal[i] = 0;
    }

    input(num1);
    input(num2);
    print(num1);
    print(num2);
    sum (num1,num2,total);
    print(total);

    return 0;
}

我知道之前已经问过这个问题，但我找不到一个我理解得很清楚的答案。谢谢。

Answer 1

你应该将sumtwonums.cpp分成两个文件，以使它们有效。

sumtwonums.h

#include <iostream>
#ifndef SUMTWONUMS_H
#define SUMTWONUMS_H

const int LENGTH = 20;

struct SumTwoNums{
    public:
        int array[LENGTH];
        char c_array[LENGTH];
};
void input(SumTwoNums &s);
void sum(SumTwoNums &s1, SumTwoNums &s2, int s[]);
void print (SumTwoNums &s);
void print (int a[]);

#endif

sumtwonums.cpp

#include "sumtwonums.h"

using namespace std;


void sum(SumTwoNums &s1, SumTwoNums &s2, int s[]){
    for (int i = LENGTH-1; i >= 0; i--){
        if (s1.array[i] + s2.array[i] + s [i] > 9 && i != LENGTH-1){
            s [i] += (s1.array[i] + s2.array[i] - 10);
            s [i-1] += 1;
        }else if (s1.array[i] + s2.array[i] + s [i]<= 9 && i != LENGTH-1){
            s [i] += s1.array[i] + s2.array[i];
        }else if (i == LENGTH-1 && s1.array[i] + s2.array[i] + s [i]> 9 ){
            s[i] += s1.array[i] + s2.array[i];
            s[i-1] += 1;
        }else if (i == LENGTH-1 && s1.array[i] + s2.array[i] + s [i] <= 9 ){
            s[i] += s1.array[i] + s2.array[i];
        }else if (i == LENGTH-1 && s1.array[i] + s2.array[i] + s [i] > 9){///////
            s [i] += (s1.array[i] + s2.array[i]);                         ////Check To see if overflow
            cout << "There is an overflow" << endl;                       ///////
        }
    }
}
void input(SumTwoNums &s){
    int dig = 0;
    for (int i = 0; i < LENGTH; i++){
        s.array[i] = 0;
    }
    cout << "Please enter a number:\n";
char next;
int x = LENGTH-1;
cin.get(next);
while (next != '\n' && next != 'E' && x >= 0){  
    dig++;   
    s.c_array[x] = next;
    cin.get(next);
    x--;
}
for (int i = 1; i <= LENGTH; i++){
    if (dig != 0) {
        s.array[LENGTH - dig] = s.c_array[LENGTH - i] - '0';
        dig--;
        }
    }   
}

void print (SumTwoNums &s){
    int count = 2;
    for (int i = 0; i <  LENGTH ; i++){
        if (s.array[i] != 0 || ( s.array[i - 1] != 0 && s.array[i] == 0 && s.array[i + 1] != 0)){
                cout << s.array[i];
            if (count%3==0 && count != 0 && i != LENGTH-1){
                cout << ",";
            }
        }
        count++;
}
cout << endl;
}
void print (int a[]){
    int count = 2;
    for (int i = 0; i <  LENGTH ; i++){
        if (a[i] != 0 || ( a[i - 1] != 0 && a[i] == 0 && a[i + 1] != 0)){
                cout << a[i];
            if (count%3==0 && count != 0 && i != LENGTH-1){
                cout << ",";
            }
        }
        count++;
}
cout << endl;
}

C ++ - 未定义参考多个文件的函数

1 个答案: