Question

// This program will read in a group of test scores (positive integers from 1 to 100)
// from the keyboard and then calculate and output the average score
// as well as the highest and lowest score. There will be a maximum of 100 scores.

//

#include <iostream>
using namespace std;

float findAverage (const int[], int); // finds average of all grades
int findHighest (const int[], int); // finds highest of all grades
int findLowest (const int[], int); // finds lowest of all grades

int main()
{
   int grades[100]; // the array holding the grades.
   int numberOfGrades; // the number of grades read.
   int pos = 0; // index to the array.
   float avgOfGrades; // contains the average of the grades.
   int highestGrade; // contains the highest grade.
   int lowestGrade; // contains the lowest grade.

   // Read in the values into the array pos = 0;
   cout << "Please input a grade from 1 to 100, (or -99 to stop)" << endl;
   cin >> grades[pos];

   while (grades[pos] != -99)
   {
       cin >> grades[pos];
   }

   numberOfGrades = grades[pos]; // Fill blank with appropriate identifier
   // call to the function to find average

   avgOfGrades = findAverage(grades, numberOfGrades);
   cout << endl << "The average of all the grades is " << avgOfGrades << endl;

   // Fill in the call to the function that calculates highest grade
   highestGrade = findHighest(grades, numberOfGrades);
   cout << endl << "The highest grade is " << highestGrade << endl;
  
   // Fill in the call to the function that calculates lowest grade
   lowestGrade = findLowest(grades, numberOfGrades);
   cout << endl << "The lowest grade is " << lowestGrade << endl;
   // Fill in code to write the lowest to the screen
   return 0;
}

//********************************************************************************
// findAverage
//
// task: This function receives an array of integers and its size.
// It finds and returns the average of the numbers in the array
// precondition : array of floating point numbers
// postcondition : average of the numbers in the array
//
//********************************************************************************
float findAverage (const int grades[], int size)
{
   float sum = 0; // holds the sum of all the numbers
   for (int i = 0; i < size; i++)
   {
       sum = sum + grades[i];
   }
   return (sum / size); //returns the average
}

//****************************************************************************
// findHighest
//
// task: This function receives an array of integers and its size.
// It finds and returns the highest value of the numbers in the array
// precondition : array of floating point numbers
// postcondition : highest value of the numbers in the array
//
//****************************************************************************
int findHighest (const int grades[], int size)
{
   float highest = 0;
   for (int i = 0; i < size; i++)
   {
       if (grades[i] > highest)
       {
           highest = grades[i];
       }
   }
   return highest;
}

//****************************************************************************
// findLowest
//
// task: This function receives an array of integers and its size.
// It finds and returns the lowest value of the numbers in the array
// precondition : array of floating point numbers
// postcondition : lowest value of the numbers in the array
//
//****************************************************************************
int findLowest (const int grades[], int size)
{
   float lowest = 0;
   for (int i = 0; i < size; i++)
   {
       if (grades[i] < lowest)
       {
           lowest = grades[i];
       }
   }
   return lowest;
}

Having trouble to output the highest number, lowest number, and the average number. All I'm getting is 0 for all there. Also I using C++ as the programming language.

Answer 1

// This program will read in a group of test scores (positive integers from 1 to 100)
// from the keyboard and then calculate and output the average score
// as well as the highest and lowest score. There will be a maximum of 100 scores.

//

#include <iostream>
using namespace std;

float findAverage (const int[], int); // finds average of all grades
int findHighest (const int[], int); // finds highest of all grades
int findLowest (const int[], int); // finds lowest of all grades

int main()
{
int grades[100]; // the array holding the grades.
int numberOfGrades; // the number of grades read.
int pos = 0; // index to the array.
float avgOfGrades; // contains the average of the grades.
int highestGrade; // contains the highest grade.
int lowestGrade; // contains the lowest grade.

// Read in the values into the array pos = 0;
cout << "Please input a grade from 1 to 100, (or -99 to stop)" << endl;
    //modified
cin >> grades[pos++];//you are not incrementing index value
   //modified
while (grades[pos-1] != -99)
{   //modified
cin >> grades[pos++];
}
   //modified
numberOfGrades = pos-1; // Fill blank with appropriate identifier
// call to the function to find average

avgOfGrades = findAverage(grades, numberOfGrades);
cout << endl << "The average of all the grades is " << avgOfGrades << endl;

// Fill in the call to the function that calculates highest grade
highestGrade = findHighest(grades, numberOfGrades);
cout << endl << "The highest grade is " << highestGrade << endl;
  
// Fill in the call to the function that calculates lowest grade
lowestGrade = findLowest(grades, numberOfGrades);
cout << endl << "The lowest grade is " << lowestGrade << endl;
// Fill in code to write the lowest to the screen
return 0;
}

//********************************************************************************
// findAverage
//
// task: This function receives an array of integers and its size.
// It finds and returns the average of the numbers in the array
// precondition : array of floating point numbers
// postcondition : average of the numbers in the array
//
//********************************************************************************
float findAverage (const int grades[], int size)
{
float sum = 0; // holds the sum of all the numbers
for (int i = 0; i < size; i++)
{
sum = sum + grades[i];
}
return (sum / size); //returns the average
}

//****************************************************************************
// findHighest
//
// task: This function receives an array of integers and its size.
// It finds and returns the highest value of the numbers in the array
// precondition : array of floating point numbers
// postcondition : highest value of the numbers in the array
//
//****************************************************************************
int findHighest (const int grades[], int size)
{
float highest = 0;
for (int i = 0; i < size; i++)
{
if (grades[i] > highest)
{
highest = grades[i];
}
}
return highest;
}

//****************************************************************************
// findLowest
//
// task: This function receives an array of integers and its size.
// It finds and returns the lowest value of the numbers in the array
// precondition : array of floating point numbers
// postcondition : lowest value of the numbers in the array
//
//****************************************************************************
int findLowest (const int grades[], int size)
{
float lowest = grades[0];//   //modified
for (int i = 0; i < size; i++)
{
if (grades[i] < lowest)
{
lowest = grades[i];
}
}
return lowest;
}

output:

Please input a grade from 1 to 100, (or -99 to stop)
40
30
50
-99

The average of all the grades is 40

The highest grade is 50

The lowest grade is 30

Process exited normally.
Press any key to continue . . .

//PLS give a thumbs up if you find this helpful, it helps me alot, thanks.

//if you have any doubts, ask me in the comments