Ive spent almost 4 hours messing with this code trying to figure out whats wrong...to no avail.
I keep getting zero as the total in the displayTripCost function at the bottom, i dont know if i messed up the pointers or what when i called by reference.... Please help!!!

//Toni-Ann Mighty
//October 20, 2013
//Call By Reference

#include <stdio.h>
#include <stdlib.h>
#define pause system("pause")
#define cls system("cls")

//Lets Prototype
void getUserInput(int *millage, int *price, int *mpg);
int getChoice();
void displayMenu();
void updateCurrentMillage(int *millage);
void updatePricePerGallon(int *price);
void displayTripCost(int,int,int);

    int choice=0,currentMillage=0, MPG=0;
    int pricePerGallonOfGas=0;

    getUserInput(&currentMillage, &pricePerGallonOfGas, &MPG);

    do {

        choice = getChoice();
        switch (choice) {
        case 1:
        case 2:
        case 3: 
            displayTripCost(currentMillage, pricePerGallonOfGas, MPG);
        } //end switch
    } while(choice!=4);

}//end main

void getUserInput(int *millage, int *price, int *mpg){
    printf("Please enter your current millage\nin other words how many miles have you driven?: \n");
    printf("\nPlease enter the price per gallon of gas: \n");
    scanf_s("%i", price);
    printf("\nPlease enter the MPG of your car: \n");
    printf("Thank You\n");
}//end getUserInput

int getChoice(){
    int result;
    do {
      scanf_s("%i", &result);
      if(result < 1 || result > 4){
        printf("Error! I said to enter between 1-4!\n");
      }//end if
    } while (result < 1 || result > 4);
    return result;
} //end function getChoice

void displayMenu(){
    printf("Main Menu\n\n");
    printf("1.Update Your Current Millage\n");
    printf("2.Update Your Total Spent of Gas\n");
    printf("3.View The Total Cost of your trip\n");
    printf("Please Make a selection..");
}//end display menu

void updateCurrentMillage(int *millage){

    printf("How miles have you driven in total now?\n\n ");
    printf("\nYour Milliage has been updated\n");
}//end updateCurrentMillage

void updatePricePerGallon(int *price){
    printf("How much does a gallon of gas cost now?\n\n");
    printf("\nThe price of gas has been updated\n");
}//end updatePricePerGallon

void displayTripCost(int millage, int cost, int mpg){
    int math = cost/mpg, total = millage * math;
    printf("The cost of your trip is %i \n",total);
}//end displayTripCost

Recommended Answers

If you want your calculations to be accurate at all, you need to use doubles or floats.

Integer division is especially (spectacularly) diabolical.

And "millage"? Really?

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If you want your calculations to be accurate at all, you need to use doubles or floats.

Integer division is especially (spectacularly) diabolical.

And "millage"? Really?

Thank you so much!! I didnt know intergers did such damage in this situation :O Your solution worked! Thanks again. As for millage, thats how my instructor spelled it in the pdf directions so i just blindly copied. Probably would have googled if i had to spell it myself xD

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