Implicit declaration of function even after header inclusion [closed] - c

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I'm having trouble using both the functions listed below in my c program main because of the implicit declaration error to the twos function. Could someone please advise.
Thanks!
#include <stdio.h>
#include <stdlib.h>
float twoxaverage(int n, float t__scores[]);
float getaverage(int n, float t_scores[])
{ int sum=0; float average=0; int i;
for (i=0; i<n; i++)
{
sum=sum + t_scores[i];
}
average=(float)sum/(float)n;
return(average);
}
float twoxaverage(int n, float t__scores[])
{ float mult;
mult=2*(getaverage( n, t__scores));
return (mult);
}
int main()
{
int t_score[]={1,2,3,4};
float twox;
twox=twoaverage4,t_score);
float twoxaverage(int n, float t__scores[]);
return 0;
}

Answer 1

Your main should move from:
int main(){
int t_score[] = { 1, 2, 3, 4 }; float twox;
twox = twoaverage4, t_score); float twoxaverage(int n, float t__scores[]);
return 0;
}
TO:
int main(){
int t_score[] = { 1, 2, 3, 4 };
float twox;
twox = twoxaverage(4, t_score);
return 0;
}
as a start.
I might also simplify your:
float getaverage(int n, float t_scores[]){
int sum=0; float average=0; int i;
for (i=0; i<n; i++){
sum=sum + t_scores[i];
}
average=(float)sum/(float)n;
return(average);
}
TO:
float getaverage(int n, float t_scores[]){
float average=0; int i;
for (i=0; i<n; i++){
average = average + t_scores[i];
}
return(average / (float)n);
}
This uses one less variable and performs the same math.

Answer 2

In this line you have at least two typos in one identifier
twox=twoaverage4,t_score);float twoxaverage(int n, float t__scores[]);
Instead of
twox=twoaverage4,t_score);
there shall be
twox = twoxaverage(4,t_score);
Also the declaration of the function that follows is unnecessary. So instead of
twox=twoaverage4,t_score);float twoxaverage(int n, float t__scores[]);
you can write simply
twox = twoxaverage(4,t_score);
I think you have not only to get the average but also to output it. So you could at least add statement
std::cout << twox << std::endl;
Or if it is a C program then you could use printf instead of C++ operator << to output twox
Also take into account that your function getaverage is wrong. You convert float numbers to int when add them to sum
float getaverage(int n, float t_scores[])
{ int sum=0; float average=0; int i;
for (i=0; i<n; i++)
{
sum=sum + t_scores[i];
}
average=(float)sum/(float)n;
return(average);
}
The valid function could look the following way
float getaverage( int n, const float t_scores[] )
{
float sum = 0.0f;
for ( int i = 0; i < n; i++ )
{
sum += t_scores[i];
}
return ( n == 0 ? 0.0f : sum / n );
}
Or if you use an old C compiler then the function can be written as
float getaverage( int n, const float t_scores[] )
{
float sum = 0.0f;
int i = 0;
for ( ; i < n; i++ )
{
sum += t_scores[i];
}
return ( n == 0 ? 0.0f : sum / n );
}
Function twoxaverage could be simplified the following way
inline float twoxaverage( int n, const float t__scores[] )
{
return ( 2 * getaverage( n, t__scores ) );
}