C++ logic error - c++

Question

I got 158, 1000, and 140 for the money outputs while I played.
The original amount I put in was 100.
The total amount of money and the amount of money entered by the user aren't showing up correctly when ran.
Sometimes, the total and the amount entered displays correctly, it should be noted.
But not always, and that's a problem.
There is some logic error(s) I can't figure out. Help?
#include <iostream>
#include <cstdlib>
#include <ctime>
#include <string>
#include <stdlib.h>
using namespace std;
void switchStatementsCalculations (int &slot1, int &slot2, int &slot3, string cherries, string
oranges, string plums, string bells, string melons, string bars);
void calculateAmountEarnedByPlaying (double &money, int slot1, int slot2, int slot3,
double &total);
int main()
{
int slot1;
int slot2;
int slot3;
double money=0;
double total=0;
double amountOfMoneyEnterd=0;
int count;
string cherries = "cherries";
string oranges = "oranges";
string plums = "plums";
string bells = "bells";
string melons = "melons";
string bars = "bars";
string doAgain;
cout << "We are going to be playing a slot machine game today." << endl;
srand(time(0));
do
{
cout << "Please enter the amount of money you'd like to insert into the slot machine. We will pull the lever for you." << endl;
cin >> money;
cout << "You put in $" << money << endl;
slot1=rand()%6+1;
slot2=rand()%6+1;
slot3=rand()%6+1;
switchStatementsCalculations(slot1, slot2, slot3, cherries, oranges, plums, bells, melons, bars);
calculateAmountEarnedByPlaying(money, slot1, slot2, slot3, total);
amountOfMoneyEnterd=(amountOfMoneyEnterd+money);
cout << "Would you like to play again? Please type yes if so." << endl;
cin >> doAgain;
if(doAgain!= "yes")
{
cout << "The total amount of money you put in the slot machine is " << amountOfMoneyEnterd << endl;
cout << "The total amount of money you won is $" << total << endl;
}
}
while(doAgain=="yes");
system("Pause");
return 0;
}
void switchStatementsCalculations(int &slot1, int &slot2, int &slot3, string cherries, string
oranges, string plums, string bells, string melons, string bars)
{
switch (slot1)
{
case 1:
cout << "You got " << cherries << endl;
case 2:
cout << "You got " << oranges << endl;
break;
case 3:
cout << "You got " << plums << endl;
break;
case 4:
cout << "You got " << bells << endl;
break;
case 5:
cout << "You got " << melons << endl;
break;
case 6:
cout << "You got " << bars << endl;
}
switch (slot2)
{
case 1:
cout << "You got " << cherries << endl;
break;
case 2:
cout << "You got " << oranges << endl;
break;
case 3:
cout << "You got " << plums << endl;
break;
case 4:
cout << "You got " << bells << endl;
break;
case 5:
cout << "You got " << melons << endl;
break;
case 6:
cout << "You got " << bars << endl;
}
switch (slot3)
{
case 1:
cout << "You got " << cherries << endl;
break;
case 2:
cout << "You got " << oranges << endl;
break;
case 3:
cout << "You got " << plums << endl;
break;
case 4:
cout << "You got " << bells << endl;
break;
case 5:
cout << "You got " << melons << endl;
break;
case 6:
cout << "You got " << bars << endl;
}
}
void calculateAmountEarnedByPlaying(double &money, int slot1, int slot2, int slot3, double &total)
{
double won=0;
if(slot1==slot2 || slot1==slot3 || slot2==slot3)
{
cout << "Congratulations! You won." << endl;
won=(money * 2);
cout << "You won " << won << endl;
}
else if ((slot1==slot2 && slot1==slot3) || (slot2==slot1 && slot2==slot3) || (slot3==slot1 && slot3==slot2))
{
cout << "Congratulations! You won." << endl;
won=(money*3);
cout << "You won " << won << endl;
}
else
{
cout << "You didn't earn any money." << endl;
}
total=(total+won);
}

Answer 1

One mistake is this in your calculateAmountEarnedByPlaying function:
double won;
You did not initialize this variable, thus it contains an indeterminate value.
It is only set if you've won something, but not set if you didn't win. You then do this at the end of your function:
total = (total + won);
If won is not initialized, then total will also be set to an indeterminate value (or undefined behavior occurs).
The won variable should be initialized to 0:
double won = 0;
Most compilers give a warning if you access an uninitialized variable like this. Please check that you have your warnings on to detect these issues.
The other issue is that you forgot a break in your switch statements:
switch (slot1)
{
case 1:
cout << "You got " << cherries << endl; // no break statement
case 2:
cout << "You got " << oranges << endl;
break;
If slot1 is 1, it will print both sets of output for case 1 and case 2.
None of this would be necessary if you used arrays instead of 6 separate variables and 6 separate lines of output:
std::string slot_items[] = {"cherries", "oranges", "plums", "bells", "melons", "bars"};
//...
int slots[3];
//...
for (int i = 0; i < 3; ++i)
slots[i] = rand()%6+1;
//...
// inside the function...
//...
for (int i = 0; i < 3; ++i)
cout << "You got " << slot_items[slots[i]] << endl;
A two line for loop replaces 60 lines of switch and case statements.