使用c中的用户输入和函数计算数组的总和和平均值

Question

beginner C coder here and I'm trying to figure out what exactly is going wrong with my code. I'm using two functions to calculate the sum and average of an array that a user inputted. The size of the array is determined by the user. I've tried looking up examples but am not finding many helpful tips. It's more likely that I'm just not understanding what I'm doing wrong. Can anyone please grant me some constructive criticism and guidance. Thank you!

#include<stdio.h>

/*function declarations*/
int addNumbers(int number[]); 
float avgNumbers(int sum, int n);

int main(){
    int i, n, number[100], sum, result;
    float average;

    printf("How many numbers do you want to enter?\n");
    scanf("%d",&n);

    for (i = 0; i < n ; i++)  
   {
       printf("Enter the numbers %d:\n", i+1);
       scanf("%d",&number[i]);
   }
    for (i = 0; i < n ; i++)  
    {
       sum = 0;
       sum = addNumbers(&number);
       average = avgNumbers(sum,n);
    }

    printf("Sum: %d\n",sum);
    printf("Average: %f\n",average);

    return 0;
}

/*function returning the sum of the numbers*/
int addNumbers(int number[])
{
    int i, n, sum;
    for (i = 0; i < n ; i++)
    sum += number[i]; 
    return sum;
    }

/*function returning the average of the numbers*/
float avgNumbers(int sum, int n)
{
    average = sum/n
    return average;
    }

Answer 1

There is no need of for loop while calling addNumbers() and avgNumbers(). Also you are sending the address in place of value in method. Replace your code with this code.

sum = 0;
sum = addNumbers(number);
average = avgNumbers(sum,n);

Answer 2

You no need loop in the main function because of you already a loop in your addNumber(int number[]) but you need to pass the number of elements in the array as an argument to addNumbers(int number[], int n) like this. And you are assigning sum = 0 in the for loop every time. In avgNumbers(int sum, int n ) you need to declare average and assign 0 to it.

Your code should be like this.

#include<stdio.h>

/*function declarations*/
int addNumbers (int number[], int n);
float avgNumbers (int sum, int n);

int main (){
    int i, n, number[100], sum, result;
    float average;

    printf ("How many numbers do you want to enter?\n");
    scanf ("%d", &n);
    for (i = 0; i < n; i++){
        printf ("Enter the numbers %d:\n", i + 1);
        scanf ("%d", &number[i]);
    }
    sum = 0;
    sum = addNumbers(number, n);
    average = avgNumbers(sum, n);


    printf ("Sum: %d\n", sum);
    printf ("Average: %f\n", average);
    return 0;
}

/*function returning the sum of the numbers*/
int addNumbers (int number[], int n){
    int i, sum=0;
    for (i = 0; i < n; i++)
        sum += number[i];
    return sum;
}

/*function returning the average of the numbers*/
float avgNumbers (int sum, int n){
    float average = 0;
    average = sum / n;
    return average;
}

Answer 3

First of all you are using return type float while calculating average but the parameters are int . In this case when you divide sum by n only the integer part is stored and hence the average value you will obtain be incorrect. You must typecast your value before actually performing division. Typecasting is very necessary else incorrect results may be produced.

The next thing is you donot need for loop in the main function

#include<stdio.h>
/*function declarations*/
int addNumbers (int number[], int n);
float avgNumbers (int sum, int n);

int main (){
    int i, n, number[100], sum, result;
    float average;

    printf ("How many numbers do you want to enter?\n");
    scanf ("%d", &n);
    for (i = 0; i < n; i++){
        printf ("Enter the numbers %d:\n", i + 1);
        scanf ("%d", &number[i]);
    }
    sum = 0;
    sum = addNumbers(number, n);
    average = avgNumbers(sum, n);


    printf ("Sum: %d\n", sum);
    printf ("Average: %f\n", average);
    return 0;
}

/*function returning the sum of the numbers*/
int addNumbers (int number[], int n){
    int i, sum=0;
    for (i = 0; i < n; i++)
        sum += number[i];
    return sum;
}

/*function returning the average of the numbers*/
float avgNumbers (int sum, int n){
    float average = 0;
    average = (float)sum / n;
    return average;
}