Thread: Wierd sign in my program (beginner)

Hi everyone,

This is my first post on here. I am currently following a c programming introduction course (I don't have any experience in programming). I am programming in Kate on Linux (virtual machine).

I am currently working on making a basic calculator. I am getting there, I am only missing a function to convert a 16 bit binary imput to decimal value, doing research on how to do that best now.

However, I am getting something wierd when I execute the program. There is a � sign before "Result: x". Sometimes it is not a � but a '.' or '/'. I am not sure how it can be removed. Any help would be great!

PS.
I know that this program can be written in fewer lines, however my priority is on making a working program first.

Code:

#include <stdio.h>

int main(void)
{
    int b, x;
    float res, a;
    char c, bord;
    res = 0;
    
    printf("** Calculator **\n");
    
    while (c != '=')
    {
    printf("Binary or decimal? (b/d) ");
    scanf(" %c", &bord);
    switch(bord)
    {
        case 'd':   printf("Value? ");
                    scanf(" %f", &a);
                    printf("Input: %.0f\n", a);
                    printf("Operation? ");
                    scanf(" %c", &c);
                    printf(" %c", &c);
                    switch(c)
                    {
                        case '+':   res = a + res;
                                    break;
                        case '-':   res = res - a;
                                    break;
                        case '/':   res = res / a;
                                    break;
                        case '*':   res = a * res;
                                    break;
                        case 'c':   res = 0;
                                    break;
                        default:    res = res;
                                    break;   
                    }
                    break;
        //Make a function for converting binary values
        /*case 'b':   printf("Value? ");
                    scanf(" %f", &a);
                    x = read_binary_value();
                    printf("Input: %f.0\n", x);
                    printf("Operation? ");
                    scanf(" %c", &c);
                    printf(" %c", &c);
                    switch(c)
                    {
                        case '+':   res = x + res;
                                    break;
                        case '-':   res = res - x;
                                    break;
                        case '/':   res = res / x;
                                    break;
                        case '*':   res = x * res;
                                    break;
                        case 'c':   res = 0;
                                    break;
                        default:    res = res;
                                    break;   
                    }
                    break;*/
        default:    a = 0;
                    printf("Operation? ");
                    scanf(" %c", &c);
                    printf(" %c", &c);
                    switch(c)
                    {
                        case '+':   res = a + res;
                                    break;
                        case '-':   res = res - a;
                                    break;
                        case '/':   res = res / a;
                                    break;
                        case '*':   res = a * res;
                                    break;
                        case 'c':   res = 0;
                                    break;
                        default:    res = res;
                                    break;   
                    }
                    break;
                            
    }
    printf("Result = %.2f\n", res);
    }  
}

Originally Posted by GReaper

When you're printing a single character with "%c", you don't need and don't want ambersand( & ) there. Lines #23 and #67.

Thank you! I updated it, now the wierd sign is gone. However I am still getting my operator sign printed there, like so:

Code:

** Calculator **
Binary or decimal? (b/d) d
Value? 5
Input: 5
Operation? +
+Result = 5.00

When i add \n after the print function for the operator, I get the following:

Code:

** Calculator **
Binary or decimal? (b/d) d
Value? 5
Input: 5
Operation? +
+
Result = 5.00

This suggest (to me at least) that the malfunction is somewhere between that print function and the result. I can't find it this.

I have also tried placing the print function of the result infront of the last break, but that did not change anything.

Do you know how I can remove the 2nd operator sign?

Oh damn, nevermind. Thanks haha, that was stupid of me.