Linked list add() method in C - c

Question

Where is error the following code?
addNode() function is not run, neither is the traverse() function.
Last data is not shown.
#include <stdio.h>
#include <stdlib.h>
struct isimler{
char isim[10];
struct isimler *next;
};
typedef struct isimler node;
node *head;
void createList(){
int k, n;
node *po;
printf("Eleman Sayisi: "); scanf("%d", &n);
for(k = 0; k<n; k++){
if(k == 0){
head = (node *) malloc(sizeof(node));
po = head;
}else{
po->next = (node *) malloc(sizeof(node));
po = po->next;
}
printf("Isim Girin: "); scanf("%s",po->isim);
}
po->next = NULL;
}
void addNode(){
node *po, *newNode;
po = head;
while(po != NULL){
po = po->next;
}
po = (node *) malloc(sizeof(node));
printf("Isim Girin: "); scanf("%s", po->isim);
po->next = NULL;
}
void traverseList(){
node *po;
int i=0;
po = head;
while(po != NULL){
printf("%d.\t%s\n",i,po->isim);
po = po->next;
i++;
}
}
int main(){
createList();
traverseList();
addNode();
traverseList();
return 1903;
}

Answer 1

Your current addNode() method creates a new node but it doesn't add it to your linked list.
You need to modify your addNode() method like so:
void addNode(){
node *po, *newNode;
po = head;
while(po->next != NULL) { // change this so you don't lose the end of the list
po = po->next; // po is now pointing to the last node in the list
}
newNode = (node *) malloc(sizeof(node)); // change this to newNode
printf("Isim Girin: "); scanf("%s", newNode->isim);
po->next = newNode; // add the new node here, don't set it to NULL
newNode->next = NULL;
}

Answer 2

You can have look this code and get to know where exactly you are having problem
#include<stdio.h>
#include<stdlib.h>
#include<stdbool.h>
struct test_struct
{
int val;
struct test_struct *next;
};
struct test_struct *head = NULL;
struct test_struct *curr = NULL;
struct test_struct* create_list(int val)
{
printf("\n creating list with headnode as [%d]\n",val);
struct test_struct *ptr = (struct test_struct*)malloc(sizeof(struct test_struct));
if(NULL == ptr)
{
printf("\n Node creation failed \n");
return NULL;
}
ptr->val = val;
ptr->next = NULL;
head = curr = ptr;
return ptr;
}
struct test_struct* add_to_list(int val, bool add_to_end)
{
if(NULL == head)
{
return (create_list(val));
}
if(add_to_end)
printf("\n Adding node to end of list with value [%d]\n",val);
else
printf("\n Adding node to beginning of list with value [%d]\n",val);
struct test_struct *ptr = (struct test_struct*)malloc(sizeof(struct test_struct));
if(NULL == ptr)
{
printf("\n Node creation failed \n");
return NULL;
}
ptr->val = val;
ptr->next = NULL;
if(add_to_end)
{
curr->next = ptr;
curr = ptr;
}
else
{
ptr->next = head;
head = ptr;
}
return ptr;
}
struct test_struct* search_in_list(int val, struct test_struct **prev)
{
struct test_struct *ptr = head;
struct test_struct *tmp = NULL;
bool found = false;
printf("\n Searching the list for value [%d] \n",val);
while(ptr != NULL)
{
if(ptr->val == val)
{
found = true;
break;
}
else
{
tmp = ptr;
ptr = ptr->next;
}
}
if(true == found)
{
if(prev)
*prev = tmp;
return ptr;
}
else
{
return NULL;
}
}
int delete_from_list(int val)
{
struct test_struct *prev = NULL;
struct test_struct *del = NULL;
printf("\n Deleting value [%d] from list\n",val);
del = search_in_list(val,&prev);
if(del == NULL)
{
return -1;
}
else
{
if(prev != NULL)
prev->next = del->next;
if(del == curr)
{
curr = prev;
}
else if(del == head)
{
head = del->next;
}
}
free(del);
del = NULL;
return 0;
}
void print_list(void)
{
struct test_struct *ptr = head;
printf("\n -------Printing list Start------- \n");
while(ptr != NULL)
{
printf("\n [%d] \n",ptr->val);
ptr = ptr->next;
}
printf("\n -------Printing list End------- \n");
return;
}
int main(void)
{
int i = 0, ret = 0;
struct test_struct *ptr = NULL;
print_list();
for(i = 5; i<10; i++)
add_to_list(i,true);
print_list();
for(i = 4; i>0; i--)
add_to_list(i,false);
print_list();
for(i = 1; i<10; i += 4)
{
ptr = search_in_list(i, NULL);
if(NULL == ptr)
{
printf("\n Search [val = %d] failed, no such element found\n",i);
}
else
{
printf("\n Search passed [val = %d]\n",ptr->val);
}
print_list();
ret = delete_from_list(i);
if(ret != 0)
{
printf("\n delete [val = %d] failed, no such element found\n",i);
}
else
{
printf("\n delete [val = %d] passed \n",i);
}
print_list();
}
return 0;
}