Problem clearing buffer, could use some help.

[kelharis]

Hello,

I am writing a program that will run once, and once done, ask the user if they would like to use it again. It has to work with any answer beginning with "y". I am having trouble with clearing the buffer when I answer "yes" or anything other than "y" itself. It works perfectly when "y" is entered, now I just need to somehow accept the other yes words and clear the buffer once the "y" has been consumed. code is as follows:

#include <stdio.h>
 
main ()
 
{
 
 
     fputs("This program will calculate a table showing the voltage,"
           "total resistance, and current for each increment of "
           "resistance given the input from the user\n\n", stdout);
 
 
     int ch, reply = 'y';
     double initcur, endcur, inccur, voltage, current;
 
 
       while ( reply == 'y' )
 
 
     {
         fputs("Enter voltage: ", stdout);
         scanf("%lf", &voltage);
         fputs("Enter initial resistance value: ", stdout);
         scanf("%lf", &initcur);
         fputs("Enter ending resistance value: ", stdout);
         scanf("%lf", &endcur);
         fputs("Enter incremental resistance value: ", stdout);
         scanf("%lf", &inccur);
 
         fputs("Table of induced currents\n\n", stdout);
         fputs("     Voltage     Total Resistance     Current\n\n",
         stdout);
         fputs("     ----------------------------------------\n\n",
         stdout);
 
 
         for (initcur; initcur <= endcur ; initcur += inccur )
         {
           current = voltage / initcur ;
 
           printf("        %.2f            %.4f        %.4f\n",
voltage, initcur, current);
         }
 
       fputs("\nEnd of table.\n\n", stdout);
 
       fputs("Would you like another computation? ", stdout);
       while ((reply = getc(stdin)) !='\n');
       scanf("%c", &reply);
 
 
      }
 
       return 0;
 
}

I am supposed to be using the getc function, not fflush, so if you can tell where I might be going wrong, I would me most appreciative. :)

[AdrianH]

Hello,

I am writing a program that will run once, and once done, ask the user if they would like to use it again. It has to work with any answer beginning with "y". I am having trouble with clearing the buffer when I answer "yes" or anything other than "y" itself. It works perfectly when "y" is entered, now I just need to somehow accept the other yes words and clear the buffer once the "y" has been consumed. code is as follows:

#include <stdio.h>
 
main ()
 
{
 
 
     fputs("This program will calculate a table showing the voltage,"
           "total resistance, and current for each increment of "
           "resistance given the input from the user\n\n", stdout);
 
 
     int ch, reply = 'y';
     double initcur, endcur, inccur, voltage, current;
 
 
       while ( reply == 'y' )
 
 
     {
         fputs("Enter voltage: ", stdout);
         scanf("%lf", &voltage);
         fputs("Enter initial resistance value: ", stdout);
         scanf("%lf", &initcur);
         fputs("Enter ending resistance value: ", stdout);
         scanf("%lf", &endcur);
         fputs("Enter incremental resistance value: ", stdout);
         scanf("%lf", &inccur);
 
         fputs("Table of induced currents\n\n", stdout);
         fputs("     Voltage     Total Resistance     Current\n\n",
         stdout);
         fputs("     ----------------------------------------\n\n",
         stdout);
 
 
         for (initcur; initcur <= endcur ; initcur += inccur )
         {
           current = voltage / initcur ;
 
           printf("        %.2f            %.4f        %.4f\n",
voltage, initcur, current);
         }
 
       fputs("\nEnd of table.\n\n", stdout);
 
       fputs("Would you like another computation? ", stdout);
       while ((reply = getc(stdin)) !='\n');
       scanf("%c", &reply);
 
 
      }
 
       return 0;
 
}

I am supposed to be using the getc function, not fflush, so if you can tell where I might be going wrong, I would me most appreciative. :)

You have to use getc to clear the buffer? Because you could use scanf("%*[^\n\r]%*[\n\r]"); The first format reads a line upto but not including the carraige return/line feed, the second reads all the carraige return/line feed after that.

I've seen you use scanf so it shouldn't be prohibited or anything.

Hope this helps,


Adrian