Thread: C (Not ++) Console Application

I think i found an alternative to scanf/fscanf and that is scanf_s.
So I have my inputs working, I dont know if they are saving for later usage however.

[1]- I am currently stuck trying to calculate the base*exp for case 3, I cannot tie in my methods to make it work. I'd like some elaboration in this area of switches.

[2]- I also would like to know how to 'clear' the previous menu, as the current code will keep repeating the menu when returned to main, which is messy; how can i clear/prevent the menu from repeating itself over and over again?

Code:

#include<stdio.h>
#include<conio.h>

int main()
{
	
    int selection = 0;
    int base = 1;
    int exponent = 1;

    printf("\nPower Menu:\n");
    printf("  1. Change Base\n");
    printf("  2. Change Exponent\n");
    printf("  3. Display base raised to exponent\n");
    printf("  4. Exit Program\n"); 
    printf("Option:");

    scanf_s("%d", &selection, 4);

    switch(selection)
    {
        case 1:
             printf("Enter Base :");
	     printf("Base = %d\n", base, scanf_s("%d", &base, stdin)); 
             return main(); 
        case 2:
             printf("Enter Exponent :");
	     printf("Exponent = %d\n", exponent, scanf_s("%d", &exponent, stdin)); 
             return main();
        case 3:
             printf("The Sum is\n");
             return main();
        case 4:
             printf("Exiting Program\n");
             return 0;
        default:
             printf("Invalid Choice\n");
			 return main();
    }
    
    return main();
}

Well if you want to avoid using the scanf function you could try the getchar function? Like...

Code:

#include <stdio.h>

int main()
{
     int ch;
     
     printf("\n Menu:\n\n");
     printf(" 1. Base\n");
     printf(" 2. Exponent\n");
     printf(" 3. B Raised To Exp\n");
     printf(" 4. Exit \n");
     printf("\n Selection?\n\n");
     
     ch = getchar();
     
     switch( ch )
     {
        case 1: 
             /* ... */
             break;
     }

Ofcourse you might have to include some error checking there!

ssharish

Originally Posted by MittWaffen

-Selectable via keyboard key (%d) press or if simple enough using arrow keys (If it isnt going to complicate my understanding)

If your compiler supports it (ex. VC++) you can use the getch() function (#include <conio.h> for that).

Try this...

Code:

#include<stdio.h>

int main()
{
    int selection;

    printf("Power Menu:\n");
    printf("1. Change base\n");
    printf("2. Change exponent\n");
    printf("3. Display base raised to exponent\n");
    printf("4. Exit Program\n"); 

    scanf("%d",&selection);
    
    switch(selection)
    {
        case 1:
             printf("Enter Base\n");
             break;
        case 2:
             printf("Enter Exponent\n");
             break;
        case 3:
             printf("The sum is..\n");
             break;
        case 4:
             printf("Exiting Program");
             return 0;
        default:
             printf("You entered an invalid choice\n");
    }
    
    return 0;
}

Seems to be working fine for me

ssharish

i use dev-c++. Did you try my code?

ssharish

Corrected, I retyped it into notepad, then entered it on a clean source file. Weird..
VS 2010 sucks so far, stupid issues that shouldn't even occur happen. Might have to download 2008 to be safe from here on out.

Regardless, I'm not trying to tie getch() instead of scanf; then try to make calculations based on this.

would this be the proper alternative...?
I cannot make this method work.

---------
int selection;
to (stays the same)
int selection;
----------
scanf("%d",&selection)
to
selection=getch();
---------

Code:

#include<stdio.h>

int main()
{
    int selection;

    printf("Power Menu:\n");
    printf("1. Change base\n");
    printf("2. Change exponent\n");
    printf("3. Display base raised to exponent\n");
    printf("4. Exit Program\n"); 
    printf("Option?");

    scanf("%d",&selection);
    
    switch(selection)
    {
        case 1:
             printf("Enter Base\n");
             break;
        case 2:
             printf("Enter Exponent\n");
             break;
        case 3:
             printf("The sum is..\n");
             break;
        case 4:
             printf("Exiting Program");
             return 0;
        default:
             printf("You entered an invalid choice\n");
    }
    
    return 0;
}

>I have also tried (int selection either way the issue still occurs unless char is used.
Thats would mean different when it comes to switch statement. the case '1': means really case 49: As it will converted to 49.

This would eventually jump to the default part. Because the selection would contain the values between 1-4, but not 49.

Can you try put a printf statement just after scanf to check what value does the selection varibale holds before executing switch statemnt. For the sake of debugging?

ssharish

Never come across such a behavior before with the any code, being working after copying into a new file. Though it might be down to the file like .o. Should have deleted the object files and try recompiling them again. Would have been interesting to find the behavior.

ssharish