converting four programs into four functions

[37poizwU]

Here is the problem :

Using FUNCTIONS,combine all four given programs into a single program.
Each part should have its own function (basically you’re converting FOUR programs into FOUR functions). The different functions should be accessible through a menu that resembles the following:
1) Array Review
2) If-Else Review
3) Loop Review 1
4) Loop Review 2
Choose a number:
If you enter the number 1, for example, it should read 5 numbers from numbers.txt and calculate the average (part 1 of the in-class assignment).

Here is what I have so far :

#include<iostream>
#include<fstream>
using namespace std;

//Function prototypes
float getAverage ();
int getScore ();
int getSum ();
int getFactorial();

int main() {


int arrayReview,IfelseReview, loopReview1, loopReview2 ;

arrayReview = 1;
IfelseReview = 2;
loopReview1 = 3;
loopReview2 = 4;


// Dispaly the menu and get a choice.

cout << "1)Array Review\n";

cout << "2)If-Else Review\n";

cout << "3) Loop Review 1\n";

cout << "4) loop Review 2 \n\n";

cout << "choose a number:\n " ;
cin >> arrayReview >> IfelseReview >> loopReview1 >> loopReview2;

return 0;
}

float getAverage ()

{
int num[5];
int temp = 0;
float average = 0;



ifstream infile;


infile.open("numbers.txt");



for(int i = 0; i < 5; i++) {


infile >> num[i];

temp += num[i];


average = temp / 5.0;

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

infile.close();
return average;

}

}
int getScore ()
{ int score;

cout << "Enter score: ";


if(score >= 90 && score <= 100)
cout << "Grade: A" << endl;
else if(score >= 80 && score < 90)
cout << "Grade: B" << endl;
else if(score >= 70 && score < 80)
cout << "Grade: C" << endl;
else if(score >= 60 && score < 70)
cout << "Grade: D" << endl;
else if(score >= 0 && score < 60)
cout << "Grade: F" << endl;
else
cout << "INVALID SCORE" << endl;

return score;

}

int sum ()

{
int num;
int sum = 0;


for(int i = 0; i < 5; i++) {
cin >> num;
sum += num;

cout << "Sum: " << sum;
return sum ;
}
}

int getFactorial()

{
int num;
int factorial = 1;
ofstream outfile;

outfile.open("factorial.txt");

cout << "Enter number: ";
cin >> num;

outfile << num << "!" << endl;

while(num != 0) {
factorial *= num;
outfile << num;

if(num != 1)
outfile << " x ";

num--;
}

outfile << " = " << factorial;

outfile.close();
return factorial ;

}


My program has no errors. Can anybody gave me some input on what's missing in my program , in order to get the correct outputs. Thanks!


for example : If you enter the number 1, for example, it should read 5 numbers from numbers.txt and calculate the average (part 1 of the in-class assignment).

[buffbill]

How can your program be error free if its not returning the correct results. You mean it compiles right? Do you know the files are opening correctly?
What average do/should you get when you enter 1? Do any of the 4 functions return a correct result?
Just a suggestion:
Why not use switch(case) and put your functions in each case block just as a temporary simplification