Problem with a while loop...

[kelharis]

I am trying to write a program using a while loop, and a nested for loop inside. The program needs to run once, and then after completion, ask if the user would like to run the program again. The while statement needs to be true while the reply is "y" and must clear the buffer afterwards (i.e. must accept "yes", "youbetcha" etc. and clear the buffer after. ) Im stuck, the program is compiling, but returns to prompt when I run it. Here is the code:

#include <math.h>
#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", stdin);
 
     char y;
     int reply, ch;
     double initcur, endcur, inccur, voltage, totresist, current;
 
       reply = y;
       while ( reply == 'y' )
 
 
     {
         fputs("Enter voltage: ", stdin);
         scanf("%f", &voltage);
         fputs("Enter initial resistance value: ", stdin);
         scanf("%f", &initcur);
         fputs("Enter ending resistance value: ", stdin);
         scanf("%f", &endcur);
         fputs("Enter incremental resistance value: ", stdin);
         scanf("%f", &inccur);
 
         fputs("Table of induced currents\n\n", stdin);
         fputs("     Voltage     Total Resistance     Current\n\n",
stdin);
         fputs("     ----------------------------------------\n\n",
stdin);
 
 
         for (initcur ; initcur<=endcur ; initcur + inccur)
         {
           current = voltage / (initcur);
 
           printf("     %2if     %4if     %4if\n", voltage, totresist,
                 current);
          }
 
       ch = getc (stdin);
 
       fputs("Would you like another computation? ", stdin);
       scanf("%c", &reply);
 
       return 0;
      }
}
 

Any help would be appreciated! :)

[RRick]

You've got your return 0 inside the while loop. This is what is causes to program to stop after just one iteration.

Move the return just past the while loop and things should improve.

[Ganon11]

Further, when initializing reply, you set it equal to y, a char variable. But you never initialized y - thus, reply holds some garbage value. You should set reply equal to the character value 'y' and get rid of the y variable.

[Haris Radoncic]

Ok so I rewrote your code abit. However, Now I came up with my own problem (im fairly new to c programming). I used a switch case within a while loop to ask the user if they want to perform the program again, but whenever they enter anything, the program simply exits. Hopefully someone can figure out why because I don't see why it would do that.

#include <stdio.h>
#include <conio.h>
 
int main (){
 
         char choice;
         float initcur, endcur, inccur, voltage, totresist, current;
 
         printf("This program will calculate a table showing\n"
         "the voltage total resistance, and current for each\n"
         "increment of resistance given the input from the user\n\n");
         printf("Would you like to run the program? ");
         scanf("%c", &choice);
 
 
         while (choice=='y'){
 
           switch(choice){
             case 'y': 
                  printf("\n\nEnter voltage: ");
                  scanf("%f", &voltage);
                  printf("Enter initial resistance value: ");
                  scanf("%f", &initcur);
                  printf("Enter ending resistance value: ");
                  scanf("%f", &endcur);
                  printf("Enter incremental resistance value: ");
                  scanf("%f", &inccur);
 
                  printf("Table of induced currents\n\n");
                  printf("      Voltage    Total Resistance    Current\n\n");
                  printf("----------------------------------------\n\n");
                  /*
                  for (initcur; initcur<=endcur; initcur=initcur+inccur)
                  {
                   current = voltage/initcur;
                   printf("      %f         %f%             f%", voltage, totresist, current);
                   printf("\n");
                  }*/
 
                    do{
                    current = voltage/initcur;
                    printf("      %f         %f%                   f%", voltage, initcur, current);
                    printf("\n");
                    initcur=initcur+inccur;
                    }         
                    while(initcur<=endcur);
 
               printf("\nWould you like to perform another computation?  ");
               scanf("%c", &choice);
               break;
 
               default:
                    {
                     printf("Is this the problem?");
                    }
 
               }
            }
    getch();
  }
 

[Haris Radoncic]

the default should actually be return(0);, i just put that statement there to see if the return was the reason for the error.