How can I get value from multiple argument in one function and print it in main function in c?

Question

currently i study in c programming language but i have a problem, is there i can get one value from multiple argument in one function and print it in main function in c?? i already create a function that come out with two argument, but somehow i need to print just one argument that only appear one process that i create more than one operation in main function.

this is my code:

#include<stdio.h>
float bakeryShop(float price_a, float price_b)
{
    float  discountA, discountB;
    discountA = price_a - (price_a*45/100);
    discountB = price_b - (price_b*60/100);
    
    printf("%.2f", discountA);
    return (discountA);
    
    printf("%.2f", discountB);
    return (discountB);
    
        
}
main()
{
char name_item_a[200];
    char name_item_b[200];
    float price_a, price_b;
    float discountA, discountB, result;
    
    
    printf("Enter item A: ");
    scanf("%s", &name_item_a);
    printf("Enter price for item A: ");
    scanf("%f", &price_a);
    
    
    printf("Enter item B: ");
    scanf("%s", &name_item_b);
    printf("Enter price for item B: ");
    scanf("%f", &price_b);
    
    printf("%s\n", name_item_a);
    bakeryShop(price_a, price_b);
    printf("%.2f", result); 
    return price_a;
    
    
    printf("%s\n", name_item_b);
    result = bakeryShop(price_a, price_b);
    printf("%.2f", result);  
    return price_b;
    
    
    
}

if you can see in the bakeryShop function, i create two process which is discountA and discountB but how to display only discount A in main function ??

because the output should be like this,

ITEM A 
Name: 
Original Price: RM 
Price after 45% discount: RM 

ITEM B 
Name: 
Original Price: 
M Price after 60% 
discount: RM

but i do not know how to get only one process discount A seperate with another process discount B

Answer 1

Your question is kind of confusing, but if I understand it correctly, then you're basically trying to calculate the discounted price of two "items" based on user input, where each item has a unique discount (price/45*100 for item A, price/60*100 for item B) - and you're stuck on trying to return the discount for both items from the function that's supposed to calculate it.

I'd approach the problem differently. Since both items A and B are defined by the same set of information (a name, a price, and a later calculated discounted price) then why not group that information together into an "Item" struct?

Another thing, since the discount is specific to each item, rather than making a function that takes multiple items as arguments, and calculates the discount for each of them separately (spawning the problem of returning multiple values, and nullifying the point of a function as you'll have to expand or contract the function dependiong on how many items you need to calculate in main) why not make a function that calculates the discount of a single item at a time, with the discount specified as an argument?

#include <stdio.h>

struct Item {
    char Name[200];

    float Price;
    float DiscountedPrice;
};

void ApplyDiscount(Item* item, float amount) {
    item->DiscountedPrice = (item->Price * amount) / 100.0;
}

// Or, if you haven't studied pointers yet..
Item ApplyDiscount(Item item, float amount) {
    item.DiscountedPrice = (item.Price * amount) / 100.0;
    return item;
}

int main() {
    Item item_a, item_b;

    printf("Item A name: ");
    scanf("%s", &item_a.Name);
    printf("Item A price: ");
    scanf("%f", &item_a.Price);

    printf("Item B name: ");
    scanf("%s", &item_b.Name);
    printf("Item B price: ");
    scanf("%f", &item_b.Price);

    ApplyDiscount(&item_a, 45);
    ApplyDiscount(&item_b, 60);

    printf("%s: %.2f\n", &item_a.Name, item_a.DiscountedPrice);
    printf("%s: %.2f\n", &item_b.Name, item_b.DiscountedPrice);
}

If you'd only like to know how to return multiple values from a function, there are multiple ways. One such way would be to write the values through pointers passed as arguments, like so

void ApplyDiscount(float item_a_price, float item_b_price, float* item_a_result, float* item_b_result) {
    *item_a_result = (item_a_price * 45.0) / 100.0;
    *item_b_result = (item_b_price * 60.0) / 100.0;
}

int main() {
    float item_a_price = 180;
    float item_b_price = 42;

    float item_a_result, item_b_result;

    ApplyDiscount(item_a_price, item_b_price, &item_a_result, &item_b_result);
}

But I wouldn't really advise this, since it can get pretty messy pretty quickly.

You could also just group the results together in a struct, but if you're doing it like that anyway, then you may as well just make an "Item" type like I previously suggested.

struct Results {
    float ResultA;
    float ResultB;
};

Results ApplyDiscount(float item_a_price, float item_b_price) {
    Results results;

    results.ResultA = (item_a_price / 45.0) * 100.0;
    results.ResultB = (item_b_price / 60.0) * 100.0;

    return results;
}

int main() {
    float item_a_price = 180;
    float item_b_price = 42;

    float item_a_result, item_b_result;

    Results results = ApplyDiscount(item_a_price, item_b_price);

    item_a_result = results.ResultA;
    item_b_result = results.ResultB;
}

Answer 2

I do believe you want to define the function like this:

float bakeryShop(float price, float discount_percent)
{
    float  discount;
    discount = price - (price*discount_percent/100);
    
    printf("%.2f", discount);
    return discount;
}

and then use it like:

 printf("%s\n", name_item_a);
 result = bakeryShop(price_a, 45);
 printf("%.2f", result); 
    
 printf("%s\n", name_item_b);
 result = bakeryShop(price_b, 60);
 printf("%.2f", result);  

Because what you did in the code above doesn't work in C at all - you cannot return multiple times from a function. If you return, you return from function once, and that's it.

So, use this function for every item separately, and it'll be usefull and meaningfull in terms of C.

Answer 3

You can not return 2 variables from a function like this.

float bakeryShop(float price_a, float price_b)
{
 
    return (discountA);
    
    return (discountB);
}

This will only return the first variable. As price_a and price_b are not connected - you can just take only 1 argument in the function. Then calling the function twice from the main method. Something like this -

float bakeryShop(float price)
{
    float  discount;
    discount = price - (price*45/100);
    return (discount); 
}
int main(){
    int price1, price2;
    scanf("%d, %d", &price1, &price2);
    float discount1 = bakeryShop(price1);
    float discount2 = bakeryShop(price2);
    printf("%.2f", discount1);
    printf("%.2f", discount2);
}