[已解决]C++ 函数的声明跟定义

wsjlarry

遇到一道题，函数中套函数，这种题应该怎么做。毫无头绪。懵逼当中。谢谢大神们帮忙解答。
题目要求：

#include <iostream>
using namespace std;
//函数声明

int main ()
{

        int number of items,  total calories;
       
        number of items= getInput();
        total calories= calcCalories(number of items);
        displayOutput(number of items, total calories);
       
        return 0;
}

//函数定义

Function name:
        1. Return type
        2. Number of formal parameters
                a. Data Type of each formal parameter
                b. Any local variables?
        3. Task performaned
        4. Comments

运行：
How many items did you eat today? 5
Eater the number of calories in each of the
5 items eaten:
Item 1: 234
Item 2: 456
Item 3: 789
Item 4: 125
Item 5: 100
Total calories eaten today = 1704
The average calories per item is 340.80

我自己写到循环的时候就不下去了，完全没有了逻辑概念， displayOutput函数里又套着calcCalories(number of items)，逻辑想不清楚了。下面是我自己写的不带函数。结果没有任何问题。愁死了

#include<iostream>
using namespace std;

int main()
{
    int i = 1;
    int  number_of_items, number_of_eachItem,calories_of_eachItem;
    int total_calories = 0;
    double average_calories;

    cout << "How many items did you eat today? ";
    cin >> number_of_items;
    cout << "Enter the number of calories in each of the\n"
        << number_of_items << " items eaten:\n";

    while (i <= number_of_items)

    {
        cout << "item " << i << ":  ";
        i++;
        cin >> calories_of_eachItem;
        total_calories += calories_of_eachItem;
    }
    cout << "Total calories eaten today = " << total_calories << "\n";
    average_calories = (static_cast<double>(total_calories))/ number_of_items;
    cout.setf(ios::fixed);
    cout.setf(ios::showpoint);
    cout.precision(2);
    cout << "The average calories per item is " << average_calories;
    return 0;
}

最佳答案

月排行榜 / 总排行榜

yuxijian2020

2021-3-24 10:16:00

我研究半天没懂你这需求里面哪里有什么函数套函数....
就单纯从第一个main函数来看,这就是写出3个函数的定义就完事了

1. #include <iostream>
   
2. using namespace std;
   
3. 
   
4. //函数声明
   
5. int getInput();
   
6. int calcCalories(int sum);
   
7. void displayOutput(int sum, int total);
   
8. 
   
9. int main ()
   
10. {
    
11. 
    
12.         int number_of_items,  total_calories;
    
13.       
    
14.         number_of_items = getInput();
    
15.         total_calories = calcCalories(number_of_items);
    
16.         displayOutput(number_of_items, total_calories);
    
17.       
    
18.         return 0;
    
19. }
    
20. 
    
21. int getInput()
    
22. {
    
23.     int sum = 0;
    
24.     printf_s("How many items did you eat today?\n");
    
25.     cin >> sum;
    
26.     //if(sum > 0)   //不太确定你这是不是要有个判断
    
27.     //{
    
28.         return sum;
    
29.     //}
    
30. }
    
31. 
    
32. int calcCalories(int sum)
    
33. {
    
34.     int temp = 0;
    
35.     int total = 0;
    
36.     printf_s("Eater the number of calories in each of the %d items eaten:\n", sum);
    
37.     for(int i = 1; i <= sum; ++i)
    
38.     {
    
39.         printf_s("Item %d: ", i);
    
40.         cin >> temp;
    
41.         total += temp;
    
42.     }
    
43. 
    
44.     return total;
    
45. }
    
46. 
    
47. void displayOutput(int sum, int total)
    
48. {
    
49.     float average = (float)total / (float)sum;
    
50.     printf_s("Total calories eaten today = %d\n", total);
    
51.     printf_s("The average calories per item is %.2f\n", average);
    
52. }

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yuxijian2020

我研究半天没懂你这需求里面哪里有什么函数套函数....
就单纯从第一个main函数来看,这就是写出3个函数的定义就完事了

1. #include <iostream>
   
2. using namespace std;
   
3. 
   
4. //函数声明
   
5. int getInput();
   
6. int calcCalories(int sum);
   
7. void displayOutput(int sum, int total);
   
8. 
   
9. int main ()
   
10. {
    
11. 
    
12.         int number_of_items,  total_calories;
    
13.       
    
14.         number_of_items = getInput();
    
15.         total_calories = calcCalories(number_of_items);
    
16.         displayOutput(number_of_items, total_calories);
    
17.       
    
18.         return 0;
    
19. }
    
20. 
    
21. int getInput()
    
22. {
    
23.     int sum = 0;
    
24.     printf_s("How many items did you eat today?\n");
    
25.     cin >> sum;
    
26.     //if(sum > 0)   //不太确定你这是不是要有个判断
    
27.     //{
    
28.         return sum;
    
29.     //}
    
30. }
    
31. 
    
32. int calcCalories(int sum)
    
33. {
    
34.     int temp = 0;
    
35.     int total = 0;
    
36.     printf_s("Eater the number of calories in each of the %d items eaten:\n", sum);
    
37.     for(int i = 1; i <= sum; ++i)
    
38.     {
    
39.         printf_s("Item %d: ", i);
    
40.         cin >> temp;
    
41.         total += temp;
    
42.     }
    
43. 
    
44.     return total;
    
45. }
    
46. 
    
47. void displayOutput(int sum, int total)
    
48. {
    
49.     float average = (float)total / (float)sum;
    
50.     printf_s("Total calories eaten today = %d\n", total);
    
51.     printf_s("The average calories per item is %.2f\n", average);
    
52. }

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wsjlarry

谢谢大神。没有嵌套，只是我自己觉得好像有。但实际就是声明跟调用，我初学函数，感觉挺难的

wsjlarry

我现在美国读书，学校封校，图书馆关闭，没有同学，老师根本就不细讲，照着教材弄几个破视频糊弄糊弄，也不带着做题。所以题见到的太少，没有针对性的练习，我现在感觉完全是自学考试，自修C++太痛苦了。您别笑话我:( 幸亏有这个平台