How do i calculate character and float number in the same if condition in C?

Question

Write a C Program to Calculate the commission of a salesman considering three regions X,Y,Z depending on the sales amount as follows:

FOR AREA CODE - X

| sales amount | Commission |
| --------     | --------   |
| <1000        | 10%        |
| <5000        | 12%        |
| >=5000       | 15%        |

-----------------------------

FOR AREA CODE - Y

| sales amount | Commission |
| --------     | --------   |
| <15000       | 10%        |
| <7000        | 12%        |
| >=7000       | 15%        |

-----------------------------

FOR AREA CODE - Z

| sales amount | Commission |
| --------     | --------   |
| <12000       | 10%        |
| <5600        | 12%        |
| >=6500       | 15%        |

-----------------------------

I take the input as a character for the area code and read it, then I take the input for the sales amount and commission to calculate the commission as a float and read, after that, I check the condition like this -

    float amt, comission;
    char area;

    printf("Area code is - 'X','Y' & 'Z'");
    printf("\nEnter Your Area Code: ");
    scanf("%c", &area);
    printf("Enter Amount: ");
    scanf("%f", &amt);

    if (area == 'X' && amt < 1000)
    {
        printf("You got 10%% Commission");
        comission = ((100 - 10) * amt) / 100;
        printf("After Commision The Slaes amount is: %6.2f", comission);
        if (amt >= 1000 && amt < 5000)
        {
            printf("You got 12%% Commission");
            comission = ((100 - 12) * amt) / 100;
            printf("After Commision The Slaes amount is: %6.2f", comission);
        }

        if (amt >= 5000)
        {
            printf("You got 15%% Commission");
            comission = ((100 - 15) * amt) / 100;
            printf("After Commision The Slaes amount is: %6.2f", comission);
        }
    }

same codes for Y and Z using else if() condition. But I did not get the expected output. after read the values my program automatically terminates.

Your compiler should be complaining about that code. If it doesn't then enable more warnings. And treat warnings as errors that needs to be fixed. — Some programmer dude, Jan 30 '23 at 15:49
You shouldn't be editing the question correcting what someone suggested you to do as an answer, since that generates confusion and invalidates the answer. — mikyll98, Jan 30 '23 at 16:01
It's not a good SO etiquette to edit the question after it has received answers / comments, and invalidate them all. — Harith, Jan 30 '23 at 16:06
Tip, add a space `scanf("%c", &area);` --> `scanf(" %c", &area);` to not save whitespace characters. — chux - Reinstate Monica, Jan 30 '23 at 18:16

mikyll98 · Answer 1 · 2023-01-30T16:16:01.003

You're missing a reference operator (&) in the second scanf():

scanf("%f", amt); // <--- missing &

However, as suggested by Some programmer dude, you should be using compiler options to display warnings and errors. For example, if you just use -Wall or -Wall -Werror (supposing you're compiling with gcc) the compiler already suggests you what's wrong with your code.

with -Wall option you get a warning and the compilation succeeds but the program won't work as expected:

<source>:12:13: warning: format '%f' expects argument of type 'float *', but argument 2 has type 'double' [-Wformat=]
   12 |     scanf("%f", amt);
      |            ~^   ~~~
      |             |   |
      |             |   double
      |             float *
<source>:12:5: warning: 'amt' is used uninitialized [-Wuninitialized]
   12 |     scanf("%f", amt);
      |     ^~~~~~~~~~~~~~~~
<source>:5:11: note: 'amt' was declared here
    5 |     float amt, comission;
      |           ^~~

with -Wall -Werror, the warnings are treated as errors and the compilation doesn't even succeeds:

<source>:12:13: error: format '%f' expects argument of type 'float *', but argument 2 has type 'double' [-Werror=format=]
   12 |     scanf("%f", amt);
      |            ~^   ~~~
      |             |   |
      |             |   double
      |             float *
<source>:12:5: error: 'amt' is used uninitialized [-Werror=uninitialized]
   12 |     scanf("%f", amt);
      |     ^~~~~~~~~~~~~~~~
<source>:5:11: note: 'amt' was declared here
    5 |     float amt, comission;
      |           ^~~
cc1: all warnings being treated as errors

I suggest you to have a look at this thread, which gives you a "general smattering" on which gcc flags are useful the most.

How do i calculate character and float number in the same if condition in C?

1 Answers1