使用函数查找数组C ++的平均值

Question

the purpose of this task is to find the average of an array but not within the main, I have to call a function to do the sum and show the average.

I though my code was sound but it just returns " the average is 011014F1"

I have tried a few different ways of doing the function but I've gone wrong somewhere, maybe everywhere!

Just a heads up, im just starting out with programing.

Heres my code:

#include <iostream>
#include <vector>

using namespace std;


void printArray(int theArray[], int sizeOfarray);
float average(float numbers[], float size, float arrayAverage);

int main()
{

   int array[10] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

   printArray(array, 10);

   cout << "The average is: " << average << endl;

   return 0;
}

void printArray(int theArray[], int sizeOfarray)
{
   for (int x = 0; x < sizeOfarray; x++)
  {
    cout << theArray[x] << endl;

  }
}

float average(float numbers[], float size, float arrayAverage)
{
        double sum = 0.0;
        for (int x = 0; x < size; x++)
    {
        sum += numbers[x];
        arrayAverage = sum / size;
    }
        return (arrayAverage);
}

I had the float average function initially set as a float with int for 'numbers', 'size' and 'arrayAverage' but thought i would change them all to float so they dont clash. like converting an int to a float etc..

As i said im new to this so my logic is not really there but i think im n the right tracks.

Any idea why its returning 011014F1 and numbers like that instead of just the average of 1-10?

Any tips much appreciated!

Answer 1

average is a function, which you need to call , and print what it returns. What you are printing now is the address of that function.

Answer 2

There are a number of problems here. First:

cout << "The average is: " << average << endl;

This is simply printing out the address of the average function, not calling it. What you wanted to do was:

cout << "The average is: " << average(array, 10, 0) << endl;

Second, your method signature has all kinds of type missmatches. The expected array value type is float , yet you're passing it an array of int . This won't work, as the compiler will not allow the implicit conversion from int[] to float[] . Your size argument should be an int in the method signature as well, not float , since array sizes are always integers.

Third, the arrayAverage parameter seems to have no purpose except to possibly throw off your math. You use it as a running accumulator, which is fine, but there's no reason to pass it to the function, it could just be a local value. So, your method signature should look like this:

float average(float numbers[], int size);

Finally, your math for calulating the average of an array is wrong. You do:

for (int x = 0; x < size; x++)
{
    sum += numbers[x];
    arrayAverage = sum / size;
}

Particularly, the arrayAverage = sum / size is wrong. Or rather, is only right during the final loop iteration. Meaning this is just wasted math. It should be:

float average(float numbers[], int size) {
    double sum = 0;
    for (int x = 0; x < size; x++)
    {
        sum += numbers[x];
    }
    return sum /(double)size;
}

Answer 3

You are not passing any thing to your function average, float average(float numbers[], float size, float arrayAverage)You should pass your array as first parameter and the size of the array in the second, the third one you dont need it , I recommand you to delete itYour function will be :

float average(float numbers[], float size)
{
float average;
        double sum = 0.0;
        for (int x = 0; x < size; x++)
    {
        sum += numbers[x];
        arrayAverage = sum / size;
    }
        return (average);
}

and in your main you do a float averageResult = average(array, size); qDebug()《 averageResult;

Answer 4

#include <iostream>
#include <vector>

using namespace std;

void printArray(int theArray[], int sizeOfarray);

int main()
{
   int array[10] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
   printArray(array, 10);
   return 0;
}

void printArray(int theArray[], int sizeOfarray)
{
   for (int x = 0; x < len(theArray); x++)
  {
    average = average + theArray[x]
  }
  average = average/(len(theArray));
  cout << average;
}

Answer 5

1 : in your function "float average(float numbers[], float size, float arrayAverage)" you need not to give arrayAverage as a perimeter, it should be initialize within function scope , 2 : if you are beginners , well you will learn about pointers later, in which you will be come to know function is actually address ! 3 : using this line (cout << "The average is: " << average(array,10) << endl;) ,remember initialize float arrayAverage within function scope