Searching an array for number of occurrences - c++

Question

This code is supposed to display a menu with 6 options. create new file, display numbers, total, and average, display a sort, search for a num and tell yow how many occurrences it had, append random numbers, and display largest.
It runs and does MOST of what it is supposed to do but I just CANNOT get the searchNum function to search for the number entered.
#include <iostream>
#include <fstream>
#include <cstdlib>
#include <string>
#include <ctime>
#include <iomanip>
using namespace std;
//Function Prototypes
void menu();
string createFile();
void displayNumTotalAverage(string myFileName);
void displaySortedNums(string myFileName);
void searchNum(string myFileName);
void displayLargestNum(string myFileName);
void appendRandomNum(string myFileName);
int main()
{
int choice = 0;
string myFileName = "";
do
{
cout << "** MENU **" << endl << endl;
cout << "Current Data File: ";
cout << fixed << setprecision(2) << showpoint;
menu();
cin >> choice;
while (choice < 1 || choice > 7)
{
cout << "Menu Choice: ";
cin >> choice;
cout << endl;
}
switch (choice)
{
case 1:
myFileName = createFile();
break;
case 2:
displayNumTotalAverage(myFileName);
break;
case 3:
displaySortedNums(myFileName);
break;
case 4:
searchNum(myFileName);
break;
case 5:
displayLargestNum(myFileName);
break;
case 6:
appendRandomNum(myFileName);
break;
}
} while (choice != 7);
system("PAUSE");
return 0;
}
void menu()
{
cout << "\n\n(1) Select / create data file(.txt file extension will be added automatically)\n"
<< "(2) Display all numbers, total, and average\n(3) Display all numbers sorted\n(4) "
<< "Search for a number and display how many times it occurs\n(5) Display the largest number\n"
<< "(6) Append a random number(s)\n(7) Exit the program\n\nMenu Choice:";
}
string createFile()
{
string myFileName;
ifstream inFile;
cout << "\nName of data file: ";
cin >> myFileName;
inFile.open(myFileName);
if (inFile)
{
cout << myFileName;
}
else
{
cout << "\nFile not found, creating file.\n\n";
ofstream outFile;
outFile.open(myFileName + ".txt");
}
system("PAUSE");
return myFileName;
}
void displayNumTotalAverage(string myFileName)
{
ifstream inFile;
const int SIZE = 50;
int num[SIZE];
int count = 0;
int total = 0;
double average = 0;
inFile.open(myFileName + ".txt");
while (!inFile)
cout << "\nData File is empty" << endl << endl;
while (count < SIZE && inFile >> num[count])
count++;
inFile.close();
for (int index = 0; index < count; index++)
{
cout << num[index] << endl;
total += num[index];
}
average = (float)total / count;
cout << endl << "Total : " << total << endl << endl;
cout << "Average: " << average << endl << endl;
cout << "File Successfully Read" << endl << endl;
system("PAUSE");
return;
}
void displaySortedNums(string myFileName)
{
ifstream inFile;
inFile.open(myFileName + ".txt");
if(inFile.good())
{
const int SIZE = 50;
int num[SIZE]; int counter = 0;
while (counter < SIZE && inFile >> num[counter])
counter++;
inFile.close();
for(int idx1 = 0; idx1 < counter; ++idx1)
for(int idx2 = idx1; idx2 < counter; ++idx2)
if(num[idx1] > num[idx2])
{
int tmp = num[idx1];
num[idx1] = num[idx2];
num[idx2] = tmp;
}
for (int i = 0; i < counter; i++)
{
cout << num[i] << endl;
}
cout << endl;
}
system("PAUSE");
return;
}
void searchNum(string myFileName)
{
ifstream inFile;
inFile.open(myFileName + "txt");
const int SIZE = 50;
int num[SIZE];
bool found = false;
int position = -1;
int index = 0;
int userNum = 0;
int counter = 0;
int numCount = 0;
cout << "Search Number: ";
cin >> userNum;
cout << endl << endl;
while (index < SIZE && !found)
{
if (num[index] == userNum)
{
found = true;
position = index;
numCount++;
}
index++;
}
cout << userNum << " occurs " << numCount << " times ";
cout << "File Successfully Read\n\n";
system("PAUSE");
return;
}
void displayLargestNum(string myFileName)
{
ifstream inFile;
inFile.open(myFileName + ".txt");
const int SIZE = 50;
int nums[SIZE];
int count = 0;
int highest;
while (count < SIZE && inFile >> nums[count])
count++;
highest = nums[0];
for (int i = 0; i < SIZE; i++)
{
if (nums[i] > highest)
highest = nums[count];
}
cout << "\nLargest Number: " << highest << endl << "File Successfully Read" << endl << endl;
}
void appendRandomNum(string myFileName)
{
cout << "i am in the appendRandomNum function - option 6" << endl;
int num = 0;
int count = 0;
ofstream outFile;
outFile.open(myFileName + ".txt", ios::app);
cout << "How many random numbers: ";
cin >> count;
for (int i = 0; i < count; i++)
outFile << rand() % 10 << endl;
outFile.close();
cout << endl << "Number(s) Added" << endl << endl;
system("PAUSE");
return;
}
Can anyone please help with this?

Answer 1

I can see 2 problems in searchNum function:
The file is opened but num array is not populated with the file content
numCount will always return either 0 or 1. Remove 'found' boolean variable altogether and it will then return the correct numCount value.

Answer 2

Here are some important rules they never seem to teach in programming courses: start with something small and simple that works, add complexity a little at a time, and develop new functionality in isolation.
Suppose you have the rest of the code working perfectly, and you can produce a file called nums.txt that looks like this:
7
9
3
8
0
2
4
8
3
9
Now you want to develop and test the searchNum function. So you write a main function like this:
int main()
{
string myFileName = "nums";
searchNum(myFileName);
system("PAUSE");
return 0;
}
Then a searchNum function:
void searchNum(string myFileName)
{
}
You compile and run this, it does nothing, so far so good.
Now have it open the file, read the first number and display it:
void searchNum(string myFileName)
{
ifstream inFile;
inFile.open(myFileName + "txt");
int num;
inFile >> num;
cout << num << endl;
}
So far so good. Now iterate through the whole file:
void searchNum(string myFileName)
{
ifstream inFile;
inFile.open(myFileName + "txt");
int num;
while(inFile >> num)
{
cout << num << endl;
}
}
So far so good. Now count the 8's:
void searchNum(string myFileName)
{
ifstream inFile;
inFile.open(myFileName + "txt");
int num;
int count = 0;
while(inFile >> num)
{
cout << num << endl;
if(num == 8)
++count;
}
}
You get the idea. Using this approach you'll get clean working code, and you'll get it faster than by trying to write it all and then fix all the bugs.

Answer 3

A couple of things I noticed also in searchNum
inFile.open(myFileName + "txt"); should be inFile.open(myFileName + ".txt");, a dot is missing from the suffix.
Read the rest of the answers and get acquainted with the debugger it will save you a lot of time and frustration.
Here is your code sample with the needed corrections. Keep up the good work and invest some time for the use of a debugger.
#include <iostream>
#include <fstream>
#include <cstdlib>
#include <string>
#include <ctime>
#include <iomanip>
using namespace std;
//Function Prototypes
void menu();
string createFile();
void displayNumTotalAverage(string myFileName);
void displaySortedNums(string myFileName);
void searchNum(string myFileName);
void displayLargestNum(string myFileName);
void appendRandomNum(string myFileName);
int main()
{
int choice = 0;
string myFileName = "";
do
{
cout << "** MENU **" << endl << endl;
cout << "Current Data File: " << myFileName << (!myFileName.empty() ? ".txt" : "");
cout << fixed << setprecision(2) << showpoint;
menu();
cin >> choice;
while (choice < 1 || choice > 7)
{
cout << "Menu Choice: ";
cin >> choice;
cout << endl;
}
switch (choice)
{
case 1:
myFileName = createFile();
break;
case 2:
displayNumTotalAverage(myFileName);
break;
case 3:
displaySortedNums(myFileName);
break;
case 4:
searchNum(myFileName);
break;
case 5:
displayLargestNum(myFileName);
break;
case 6:
appendRandomNum(myFileName);
break;
}
} while (choice != 7);
cin.get();
return 0;
}
void menu()
{
cout << "\n\n(1) Select / create data file(.txt file extension will be added automatically)\n"
<< "(2) Display all numbers, total, and average\n(3) Display all numbers sorted\n(4) "
<< "Search for a number and display how many times it occurs\n(5) Display the largest number\n"
<< "(6) Append a random number(s)\n(7) Exit the program\n\nMenu Choice:";
}
string createFile()
{
string myFileName;
ifstream inFile;
cout << "\nName of data file: ";
cin >> myFileName;
inFile.open(myFileName + ".txt", std::ifstream::in);
if (inFile)
{
cout << myFileName;
}
else
{
cout << "\nFile not found, creating file.\n\n";
ofstream outFile;
outFile.open(myFileName + ".txt");
outFile.close();
}
cin.get();
return myFileName;
}
void displayNumTotalAverage(string myFileName)
{
ifstream inFile;
const int SIZE = 50;
int num[SIZE];
int count = 0;
int total = 0;
double average = 0;
inFile.open(myFileName + ".txt");
while (!inFile)
cout << "\nData File is empty" << endl << endl;
while (count < SIZE && inFile >> num[count])
count++;
inFile.close();
for (int index = 0; index < count; index++)
{
cout << num[index] << endl;
total += num[index];
}
average = (float)total / count;
cout << endl << "Total : " << total << endl << endl;
cout << "Average: " << average << endl << endl;
cout << "File Successfully Read" << endl << endl;
cin.get();
return;
}
void displaySortedNums(string myFileName)
{
ifstream inFile;
inFile.open(myFileName + ".txt");
if(inFile.good())
{
const int SIZE = 50;
int num[SIZE]; int counter = 0;
while (counter < SIZE && inFile >> num[counter])
counter++;
inFile.close();
for(int idx1 = 0; idx1 < counter; ++idx1)
for(int idx2 = idx1; idx2 < counter; ++idx2)
if(num[idx1] > num[idx2])
{
int tmp = num[idx1];
num[idx1] = num[idx2];
num[idx2] = tmp;
}
for (int i = 0; i < counter; i++)
{
cout << num[i] << endl;
}
cout << endl;
}
cin.get();
return;
}
void searchNum(string myFileName)
{
ifstream inFile;
inFile.open(myFileName + ".txt");
const int SIZE = 50;
int num[SIZE];
int position = -1;
int index = 0;
int userNum = 0;
int counter = 0;
int numCount = 0;
cout << "Search Number: ";
cin >> userNum;
cout << endl << endl;
// Fill num array with inFile numbers.
while (counter < SIZE && inFile >> num[counter++]);
while (index < SIZE)
{
if (num[index] == userNum)
{
position = index;
numCount++;
}
index++;
}
cout << userNum << " occurs " << numCount << " times ";
cout << "File Successfully Read\n\n";
cin.get();
return;
}
void displayLargestNum(string myFileName)
{
ifstream inFile;
inFile.open(myFileName + ".txt");
const int SIZE = 50;
int nums[SIZE];
int count = 0;
int highest;
while (count < SIZE && inFile >> nums[count])
count++;
highest = nums[0];
for (int i = 0; i < SIZE; i++)
{
if (nums[i] > highest)
highest = nums[count];
}
cout << "\nLargest Number: " << highest << endl << "File Successfully Read" << endl << endl;
}
void appendRandomNum(string myFileName)
{
cout << "i am in the appendRandomNum function - option 6" << endl;
int count = 0;
ofstream outFile;
outFile.open(myFileName + ".txt", ios::app);
cout << "How many random numbers: ";
cin >> count;
for (int i = 0; i < count; i++)
outFile << rand() % 10 << endl;
outFile.close();
cout << endl << "Number(s) Added" << endl << endl;
cin.get();
return;
}