discount value cannot calculate after case commad

Question

I have some problem with my homework. So this is how it looks like

#include<stdio.h>
int main()
{
    char code;
    int price,discount;
    float total;
    printf("Please input price: ");
    scanf("%d",&price);
    printf("Please input discount code: ");
    scanf(" %c",&code);
    switch(code)
    {
        case 'a':   printf("Your discount code is 25 percent\n");
                    discount = 25;
                    break;
        case 'b':   printf("Your discount code is 15 percent\n");
                    discount = 15;
                    break;
        case 'c':   printf("Your discount code is 5 percent\n");
                    discount = 5;
                    break;
        default:    printf("Wrong code,Your discount is 0 percent\n");
                    discount = 0;
                    break;
    }
    total = (price*((100-discount)/100));
    printf("Your price is = %.2f\n",total);
}

I have 2 questions to ask

My task is I have to input both of uppercase and lowercase letter for discount code (there are only three codes: a, b, c) so how can I put both of them in case command? (in this I only do the lowercase letter)
I have run this. But it seems like the discount value is 0 when I try to used it for calculate in the end. When I print the discount only, it works normally. How can I fix that?

Sorry for my poor English and Thank you for your help!

All parts of `price*((100-discount)/100)` are integers. That will give an integer result. Most notably `(100-discount)/100` will *always* be zero, To make it a floating-point calculation turn all integer literals `100` into floating-point literals `100.0`. — Some programmer dude, Jul 26 '21 at 07:25
Does this answer your question? [What is the behavior of integer division?](https://stackoverflow.com/questions/3602827/what-is-the-behavior-of-integer-division) — phuclv, Jul 26 '21 at 07:34
[Integer division always zero](https://stackoverflow.com/q/9455271/995714), [C++, my double or int value is always 0](https://stackoverflow.com/q/26650870/995714), [Why does dividing two int not yield the right value when assigned to double?](https://stackoverflow.com/q/7571326/995714) — phuclv, Jul 26 '21 at 07:37

MiniMik · Accepted Answer · 2021-07-26T07:47:31.233

1

There would be different possibilities.

scanf(" %c",&code);
switch(code)
{
    case 'a':
    case 'A':
      printf("Your discount code is 25 percent\n");
      discount = 25;
      break;

or you change the input to lower case before or in the switch!

switch( code | 0x60 ) // make it to lower case

with this you don't have to change the following code.

edited Jul 26 '21 at 07:47

answered Jul 26 '21 at 07:38

MiniMik

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10

1

If I tried to read the code in which there was switch statement with `code | 0x60`, I would probably get stuck there for a while. – whiskeyo Jul 26 '21 at 07:43
I'd prefer first suggestion for readability. – Louis Go Jul 26 '21 at 07:45
@whiskeyo: sorry, I do not get what you mean? – MiniMik Jul 26 '21 at 07:45
The value `0x60` comes out of nowhere and it is the first time I see one in such use. And because of that, the code is not very readable. – whiskeyo Jul 26 '21 at 07:51
@wiskeyo: yes, the readability isn't improved with that... You can use a define `#define LOWERCASE_BIT 0x60` and use that. The readability is much better then. – MiniMik Jul 26 '21 at 09:29

discount value cannot calculate after case commad

1 Answers1