Pointer variable using float inside an array to calculate the average C++

Question

I am trying to calculate the float using pointer variable, but I am getting an error that I cannot convert 'float*' to 'int*' in initialization. Any ideas how I would go on converting a float to an integer? Thanks a lot.

   int main()
    {
        float arr[SIZE]={1.1,2.2,3.3,4.4,5.5};
        int sum, average, avg=0;
        int* end=arr+SIZE;
        for(int* ptr=arr; ptr<end; ptr++)
        {
            sum+= *ptr; 
            avg = average/sum;

        }
        cout << "The sum is " << sum;
        cout << "The average is " << avg;

    }

why sum is an int? it makes more sense for it to be float. And you are using `average` without initialization. — esam, Nov 07 '16 at 23:32
That's the part I dont understand what to do ? Because of the converting. Cheers. — Chris Ashkar, Nov 07 '16 at 23:33
`int`s may have a different size from `float` which would make `end` pretty messed up — user4581301, Nov 07 '16 at 23:33
I suppose OP could have some complicated macro nonsense to make `cout <<` work in C, @Raindrop7 — user4581301, Nov 07 '16 at 23:35
@Raindrop7 I apologize for not clarifying it in the title its C++, I will adjust accordingly. — Chris Ashkar, Nov 07 '16 at 23:36
in your loop you are using average without initializing it + the errors — Raindrop7, Nov 07 '16 at 23:37
@user4581301 thanx for pointing that! using cout excludes being on C — Raindrop7, Nov 08 '16 at 00:02

Raindrop7 · Accepted Answer · 2016-11-07T23:49:48.417

1

you can solve it by: append 'f' to each value in the array also only calculate the average outside the loop no inside so in your program you are calculating avg after each sum!!

const int SIZE = 5; // or #define SIZE 5 // I recommend using const
float arr[SIZE] = {1.1f, 2.2f, 3.3f, 4.4f, 5.5f};
float sum = 0, avg = 0;
float* end = arr + SIZE;

    for(float* fPtr = arr; fPtr < end; fPtr++)
        sum += *fPtr; 
    avg = sum / SIZE;

    cout << "The sum is " << sum << endl;
    cout << "The average is " << avg << endl;

edited Nov 07 '16 at 23:49

answered Nov 07 '16 at 23:41

Raindrop7

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Thank you for your answer, although this does work, I can't use an integer index. – Chris Ashkar Nov 07 '16 at 23:43
Works like a charm, Thank you so much. I am so glad to join this wonderful website. – Chris Ashkar Nov 07 '16 at 23:52
@ChrisAshkar Remember: the very bad thing you were trying to do: "converting a pointer to float into an integer and inside the loop you are taking the value of this pointer to integer!! so any all the decimal part of array elements will be discarded" – Raindrop7 Nov 07 '16 at 23:57

Pointer variable using float inside an array to calculate the average C++

1 Answers1