Thread: newbie stuff

program specifications:
Write a C program to determine the eligibility of someone to vote. The program will prompt the user about his/her age, citizenship, conviction status, and voter registration status, and depending on what the user inputs, will determine whether the voter is eligible to vote or not.

I wrote a flow chart:
I have attached it here...

Based on my flowchart I tried to write this code (pasted below), which doesn't have any syntax errors that the devcpp compiler catches, but there is obviously a logic error somewhere that I can't see. I don't under stand where my problem is and my instructor for this class is...well let's just say he isn't going to help me.

Code:

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
  char c, f, r;
  int age;
  
  printf( "The purpose of this questionnaire is to determine your eligibility to vote.\n" );
  puts( "Please enter your age: " );
  scanf( "%d", &age );
  if (age >=18){
            printf("Are you a legal citizen of the United States? Please enter Y or N\n");
            scanf("%c", &c);
                }
                if (c == 'y' || 'Y'){
                        printf("Are you registered to vote? Please enter Y or N\n");
                        scanf("%c", &r);
                            }
                             if (r == 'y' || 'Y'){
                                printf("Have you been convicted of any felonies? Please enter Y or N\n");
                                scanf("%c", &f);
                                        }
                                    if ( f == 'n' || 'N'){
                                        printf("Thank you for completing this questionnaire! You are eligible to vote!\n");
                                               }
                                    else if (f =='y'||'Y'){
                                        printf("You are NOT eligible to vote!\n");
                                               } 
                               else if (r == 'n' || 'N'){
                                  printf("You are NOT eligible to vote!\n");
                                               }
                else if (c == 'n' || 'N'){
                        printf("You are NOT eligible to vote!\n");
                                               }
else if (age <18){
     printf("You are NOT eligible to vote!\n");
           } 

  system("PAUSE");	
  return 0;
}

srry if this doesn't have the correct tags the sticky wanted, I'm new to all this and I didn't understand.

Please help via post here or email [email protected]

EDIT: It looks sloppy because the post isn't reading the indents I put in...srry once again :/

Code:

if (c == 'y' || 'Y'){

Won't work - you have to write out the condition in full each time:

Code:

if (c == 'y' || c == 'Y'){

updated code:

Code:

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
  char c, f, r;
  int age;
  
  printf( "The purpose of this questionnaire is to determine your eligibility to vote.\n" );
  puts( "Please enter your age: " );
  scanf( "%d", &age );
  if (age >=18){
            printf("Are you a legal citizen of the United States? Please enter Y or N\n");
            scanf("%c", &c);
                }
                if (c == 'y' || c =='Y'){
                        printf("Are you registered to vote? Please enter Y or N\n");
                        scanf("%c", &r);
                            }
                             if (r == 'y' || r =='Y'){
                                printf("Have you been convicted of any felonies? Please enter Y or N\n");
                                scanf("%c", &f);
                                        }
                                    if ( f == 'n' || f == 'N'){
                                        printf("Thank you for completing this questionnaire! You are eligible to vote!\n");
                                               }
                                    else if (f =='y'||f == 'Y'){
                                        printf("You are NOT eligible to vote!\n");
                                               } 
                               else if (r == 'n' || r == 'N'){
                                  printf("You are NOT eligible to vote!\n");
                                               }
                else if (c == 'n' || c == 'N'){
                        printf("You are NOT eligible to vote!\n");
                                               }
else if (age <18){
     printf("You are NOT eligible to vote!\n");
           } 

  system("PAUSE");	
  return 0;
}

still doesn't execute properly, it "fails" correctly, but if the age is >18 it asks the next question then just ends w/o any user input

Tried what you suggested:

Code:

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
  char c, f, r;
  int age;
  
  printf( "The purpose of this questionnaire is to determine your eligibility to vote.\n" );
  puts( "Please enter your age: " );
  scanf( "%d", &age );
  printf("Are you a legal citizen of the United States? Please enter Y or N\n");
  scanf("%c", &c);
  printf("Are you registered to vote? Please enter Y or N\n");
  scanf("%c", &r);
  printf("Have you been convicted of any felonies? Please enter Y or N\n");
  scanf("%c", &f);
  if (age >=18 && c=='y' && f=='n' && r=='y'){
     printf("You are eligible to vote!\n");
           } 
           else if (age <18 || c=='n' || f=='y' || r=='n'){
                printf("You are NOT eligible to vote!\n");
                }

  system("PAUSE");	
  return 0;
}

did this and it still does the same thing, it will ask the age then ask the next two questions w/o pausing to get input.

The newline character is left in the standard input buffer, so you need to get rid of it.

Code:

int dummy;
...
while ((dummy = getchar()) != '\n') ;

following the scanf lines will eat everything left in the buffer, up to and including the newline.

Originally Posted by rags_to_riches

The newline character is left in the standard input buffer, so you need to get rid of it.

Code:

int dummy;
...
while ((dummy = getchar()) != '\n') ;

following the scanf lines will eat everything left in the buffer, up to and including the newline.

I'm sorry...don't blame this on me but...I have no idea what you're telling me. Blame Dr. Ruknet Cezzar

Originally Posted by laserlight

Do you understand the statement that the "newline character is left in the standard input buffer"?

I know what the newline character is, but sadly enough I have no idea about an input buffer...I'd ask my angry russian instructor but he'd just say the same thing he says to everyone else, "I can't tell you everything, you have to figure it out!"...but it would sound angry. So here I am...