Question

I am reading from stdin students in a structure array. After the details are introduced for one student, i ask for another student details. if the choice is Y, i’ll add the new student, if the choice is N, break. But what if the choice is simply ENTER? How can i detect the new line character? I tried with getchar(), but it skips the first reading from stdin.When i debug it doesn’t stops to the first line test=getchar(), it stops to the second one.

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

struct student
{
char name[20];
int age;
};

int main()
{
struct student NewStud[5];
char test;
int count=0;
for(count=0;count<5;count++)
{
    printf("Enter the details for %s student: ",count>0?"another":"a");
    printf("\nName : ");
    scanf("%s",NewStud[count].name);
    printf("\nAge : ");
    scanf("%d",&NewStud[count].age);
    printf("Would you like to continue? (Y/N)");
    test=getchar();
    if(test=='\n')
    {
        printf("Invalid input. Would you like to continue? (Y/N)");
        test=getchar();
    }
    while(tolower(test) !='n' && tolower(test) != 'y')
    {
        printf("Invalid input.Would you like to continue? (Y/N)");
        test=getchar();
    }
    if(tolower(test) == 'n')
    {
        break;
    }
    if(tolower(test) == 'y')
    {
        continue;
    }
}


getch();
}

Answer 1

The problem is that scanf() leaves a newline character in the input stream, you have to consume it before you’ll get “valid” data in getchar().

Ex:

scanf("\n%s",NewStud[count].name);
getchar();
printf("\nAge : ");     
scanf("%d",&NewStud[count].age);
getchar();
printf("Would you like to continue? (Y/N)");
test=getchar();   // Now this will work

Check out this link for more info. It’s for fgets, but it’s the same problem with getchar()