Loop and Switch Problem Help

[123456tacos]

There is my code. I'm running into problems in which the program will run, but the results are... bad. Not even close. All products except 5 show up as 0, and 5 ends up showing up as 70.xxxxxxxxxxx or something similar.

I'm very new to C programming so bear with me as I'm aware I may not even be close to what I actually need to do. Does anyone here happen to have any ideas to get this working?

Problem:Loop and Switch

A mail-order house sells five different products whose retail prices are as follows: product 1, $2.98; product 2, $4.50; product 3, $9.98; product 4, $4.49; and product 5, $6.87. Write an application that reads a series of pairs of numbers as follows:

a) Product number
b) Quantity sold for one day

Your program must use a switch structure to help determine the retail price for each product. It should calculate and display the total retail value of each product sold last week. Use a sentinel-controlled loop to determine when the program should stop looping and display the final results.

#include <stdio.h>
#define SENTINEL 0

int

main(void)

{

    int prodnum = 0;

    int quant = 0;

    double prodtot1 = 0, prodtot2 = 0, prodtot3 = 0, prodtot4 = 0, prodtot5 = 0;

    

    printf("Enter product number (1-5) (%d to stop): ", SENTINEL);

    scanf("%d", &prodnum);

    if (prodnum != SENTINEL) {

    printf("Enter quantity sold: ");

    scanf ("%d", &quant); }

    while (prodnum != SENTINEL) {

        printf("Enter product number (1-5) (%d to stop): ", SENTINEL);

        scanf("%d", &prodnum);

        printf("Enter quantity sold: ");

        scanf ("%d", &quant);

    }

    if ( prodnum==1 || prodnum==2 || prodnum==3 || prodnum==4 || prodnum==5 )

    {

    switch (prodnum) {

        case 1: prodtot1 = 2.98 * quant;

        break;

        case 2: prodtot2 = (4.50 * quant);

        break;

        case 3: prodtot3 = (9.98 * quant);

        break;

 

        case 4: prodtot4 = (4.49 * quant);

        break;

        case 5: prodtot5 = (6.87 * quant);

        break;

 

        default: printf("Invalid number selected, please enter a number 1-5.\n");

    }

    }

    printf("Product 1: %d\n", prodtot1);

    printf("Product 2: %lf\n", prodtot2);

    printf("Product 3: %lf\n", prodtot3);

    printf("Product 4: %lf\n", prodtot4);

    printf("Product 5: %lf\n", prodtot5);
    
    system ("pause"); 
    return(0);

}

[Subsonics]

You are continually overwriting prodnum and quant in your while loop, as well as, the previous amount that you entered in the if clause.

prodnum can only have 1 value, it's a single int, and your switch/case will only execute 1 case so all other cases will not be executed and the variables in them will keep their initial value of 0.

[Bayint Naung]

Develop algorithm first before coding...
1) Read prod no:
2) if prod no = END . exit
3) Read Qty sold
4) add to that prod no:

prod1 = prod2 = prod3 = ... = 0
do 
 prod_no = get_prod_no()
 if prod_no = SENTINEL 
   END
 qty_sold = get_qty_sold()
 switch  prod_no 
   case 1: prod1 += qty_sold * 2.98
   case 2:  ....

IMO, If you have learnt array, the code needs not be that long....

[123456tacos]

kk so this is what i got it works and all but when i enter multiple product #1 it just takes the last one i enter and it doesnt add them

#include <stdio.h> 

int main() 
{
  int swt=0, num1=0, num2=0, num3=0, num4=0, num5=0;
  float awn1=0, awn2=0, awn3=0, awn4=0, awn5=0;
 
  for(;;)  
  { 
    printf ("\nEnter the product number <1-5> <0 to end>: "); 
    scanf ("%d", &swt );
    if(swt==0)
      break;
  
    switch ( swt )
    { 
      case 1: 
        printf ("Enter Quantity Sold: "); 
        scanf ("%d",&num1 ); 
        awn1 = num1 * 2.98;
        break; 

      case 2: 
        printf ("Enter Quantity Sold: "); 
        scanf ("%d", &num2 ); 
        awn2 = num2 * 4.50; 
        break; 

      case 3: 
        printf ("Enter Quantity Sold: "); 
        scanf ("%d", &num3 ); 
        awn3 = num3 * 9.98; 
        break; 

      case 4: 
        printf ("Enter Quantity Sold: "); 
        scanf ("%d", &num4 ); 
        awn4 = num4 * 4.49; 
        break; 
      
      case 5: 
        printf ("Enter Quantity Sold: "); 
        scanf ("%d", &num5 ); 
        awn5 = num5 * 6.87; 
        break; 

      default: 
        printf ("Incorrect number\n"); 
        printf ("Enter your product number:"); 
    } 
  } 

   
    printf("\nProduct 1 : $%.2f\n",
    awn1);
    printf("\nProduct 2 : $%.2f\n",
    awn2);
    printf("\nProduct 3 : $%.2f\n",
    awn3);
    printf("\nProduct 4 : $%.2f\n",
    awn4);
    printf("\nProduct 5 : $%.2f\n",
    awn5);
  getch(); 
  system ("pause");  
  return 0; 
}

nvm i was just missing += lol :P