使用c查找数组的平均值

Question

我是C语言编码的新手，我正在尝试获得数组的平均值，但由于某种原因它没有计算，它给了我0.0的结果。

我该如何解决这个问题。感谢

#include <stdio.h>
float grades_average(float grades[7]);
int main() {

 float grades[7]={98.8, 97.9, 99.3, 99.8, 99.6, 99.4, 99.9};
 float average;
 average = grades_average(grades);
 printf("Average is: %.2f",average);


 return 1;
}
float grades_average(float grades[7]){
 int i;
 float sum = 0;
 float average = 0.0;
 /* calculate the sum of grades using for loop*/
    for(i = 0; i <= 7; i++){
       sum = sum + grades[7];
    }
 average = sum/7;

 return average;
}

输出结果为：

Average is: 0.00

Answer 1

最小变更解决方案：

float grades_average(float grades[7]){
 int i;
 float sum = 0;
 float average = 0.0;
 /* calculate the sum of grades using for loop*/
    for(i = 0; i < 7; i++){
       sum = sum + grades[i];
    }
 average = sum/7.f;

 return average;
}

1. 将for(i = 0; i <= 7; i++){更改为for(i = 0; i < 7; i++){。成绩的有效指标仅为0-6。 7超出界限。
2. 将sum = sum + grades[7];更改为sum = sum + grades[i];您需要一遍又一遍地检查每个元素，而不是（超出）最后一个元素。
3. 将average = sum/7;更改为average = sum/7.f; .f确保无整数除法。这在分裂期间保留了小数。

我希望有所帮助！

Answer 2

这是完整的代码。有2个变化，第20行和第23行

#include <stdio.h>
float grades_average(float grades[7]);
int main() {

 float grades[7]={98.8, 97.9, 99.3, 99.8, 99.6, 99.4, 99.9};
 float average;
 average = grades_average(grades);
 printf("Average is: %.2f",average);


 return 1;
}
float grades_average(float grades[7]){
 int i;
 float sum = 0;
 float average = 0.0;
 /* calculate the sum of grades using for loop*/

   /*Changed here to <7 because i takes 0,1,2,3,4,5,6 which are 7 elements, your code is <=7 which takes 0.......7 which are 8 elements */
    for(i = 0; i < 7; i++){

       /*Changed here to i from 7, your code everytime sums out of bound element, Garbage value since grades[7] does not exist*/
       sum = sum + grades[i];
    }
 average = sum/7;

 return average;
}

Answer 3

1. 将for(i = 0; i <= 7; i++){}更改为for(i = 0; i < 7; i++){}，因为   完全你有7个元素，从0到6。

2. 将sum = sum + grades[7];更改为sum = sum + grades[i];，因为成绩[7]只会包含数组的最后一个值，但您想要添加数组中的所有值。

   包括

   float grades_average(float grades[7]);
   int main() {
   
    float grades[7]={98.8, 97.9, 99.3, 99.8, 99.6, 99.4, 99.9};
    float average;
    average = grades_average(grades);
    printf("Average is: %.2f",average);
   
   
    return 1;
   }
   float grades_average(float grades[7]){
    int i;
    float sum = 0;
    float average = 0.0;
    /* calculate the sum of grades using for loop*/
       for(i = 0; i < 7; i++){
          sum = sum + grades[i];
       }
    average = sum/7.f;
   
    return average;
   }
   

   
   

希望有所帮助..

Answer 4

尝试将i代替7，

 sum = sum + grades[7];

像

sum = sum + grades[i];

和你的循环从0到6

Answer 5

代替使用此

 sum = sum + grades[7];

使用

sum = sum + grades[i];

然后它会起作用。