why my while loop condition not working?

Question

This program asks for number irrespective of what character you enter. Then the problem is in the while loop.

Why my while loop condition not working ? checking temp isn't equal to NULL

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

typedef struct node
{
    int num;
    struct node *ptr;
} nod;
nod *head = NULL;

void insert()
{
    int n;
    nod *temp = (struct node*) malloc(sizeof(struct node));
    printf("Enter nnumber \n");
    scanf("%d", &n);
    temp->num = n;
    temp->ptr = NULL;
    if (head == NULL)
    {
        head = temp;
    }
    else
    {
        temp->ptr = head;
        head = temp;
    }
}

void display()
{
    nod* temp;
    temp = head;
    while (temp != NULL)
    {
        printf(" --> %d", temp->num);
        temp = temp->ptr;
    }
}

int main()
{
    char ch;
    do
    {
        insert();
        display();
        char ch;
        printf("\n enter more data ? (y/n)");
        scanf("\n %c", &ch);
    }
    while (ch != 'n');
    return 0;
}

Thanks in advance

Answer 1

Why you are re-declare char ch inside the loop ?

Remove char ch inside loop and fix your problem. Like,

int main()
{
    char ch;
    do
    {
        insert();
        display();
        printf("enter more data ? (y/n)\n");
        scanf(" %c", &ch);
    }
    while (ch != 'n');    
    return 0;
}