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Q&A Question regarding an error message in my compiler to do with my code on linked list.

Can anyone help me, I'm currently learning pointers, this is the code I wrote to try and insert a node at the beginning of the list. However at the part where I included the comment of "error at th...

1 answer · posted 3y ago by hamburgersarecool‭ · edited 3y ago by hamburgersarecool‭

Question c pointers linked-list

#4: Post edited by

hamburgersarecool‭ · 2022-01-14T04:41:40Z (almost 3 years ago)

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Can anyone help me, I'm currently learning pointers, this is the code I wrote to try and insert a node at the beginning of the list. However at the part where I included the comment of "error at this line" basically my compiler gave me the error of "In function Insert: Node undeclared".
Why is it so?
```//Inserting a node at the beginning of linked list
#include<stdlib.h>
#include<stdio.h>
struct Node{
int data;
struct Node* next;
};
struct Node* head;
void Insert(int x){
Node* temp = (Node*)malloc(sizeof(struct Node)); //error at this line
temp->data = x;
temp->next = head;
head = temp;
if(head != NULL)
temp->next = head;
head = temp;
}
void Print(){
struct Node* temp = head;
printf("List is: ");
while(temp != NULL){
printf("%d", temp->data);
temp = temp->next;
}
printf("\n");
}
int main(){
head = NULL; //empty list
printf("How many numbers?\n");
int n, i;
scanf("%d", &n);
for(int i=0; i < n; i++){
printf("Enter the number\n");
scanf("%d", &x);
Insert(x);
Print();
}
}
```
First edit:
~~My program runs, lets me enter the amount of numbers I want, as well as the numbers, however it prints out only the latest number I entered. What could possibly be the problem? Thanks.~~
```//Inserting a node at the beginning of linked list
#include<stdlib.h>
#include<stdio.h>
struct Node{
int data;
struct Node* next;
};
struct Node* head;
void Insert(int x){
struct Node* temp = (struct Node*)malloc(sizeof(struct Node));
temp->data = x;
temp->next = head;
head = temp;
if(head != NULL)
temp->next = head;
head = temp;
temp->next = NULL;
}
void Print(){
struct Node* temp = head;
printf("List is: ");
while(temp != NULL){
printf("%d", temp->data);
temp = temp->next;
}
printf("\n");
}
int main(){
head = NULL; //empty list
printf("How many numbers?\n");
int n, i;
scanf("%d", &n);
for(int i=0; i < n; i++){
printf("Enter the number\n");
scanf("%d", &x);
Insert(x);
Print();
}
}
```

Can anyone help me, I'm currently learning pointers, this is the code I wrote to try and insert a node at the beginning of the list. However at the part where I included the comment of "error at this line" basically my compiler gave me the error of "In function Insert: Node undeclared".
Why is it so?
```//Inserting a node at the beginning of linked list
#include<stdlib.h>
#include<stdio.h>
struct Node{
int data;
struct Node* next;
};
struct Node* head;
void Insert(int x){
Node* temp = (Node*)malloc(sizeof(struct Node)); //error at this line
temp->data = x;
temp->next = head;
head = temp;
if(head != NULL)
temp->next = head;
head = temp;
}
void Print(){
struct Node* temp = head;
printf("List is: ");
while(temp != NULL){
printf("%d", temp->data);
temp = temp->next;
}
printf("\n");
}
int main(){
head = NULL; //empty list
printf("How many numbers?\n");
int n, i;
scanf("%d", &n);
for(int i=0; i < n; i++){
printf("Enter the number\n");
scanf("%d", &x);
Insert(x);
Print();
}
}
```
First edit:
Update: My program runs, lets me enter the amount of numbers I want, as well as the numbers, however it prints out only the latest number I entered. What could possibly be the problem? Thanks.
```//Inserting a node at the beginning of linked list
#include<stdlib.h>
#include<stdio.h>
struct Node{
int data;
struct Node* next;
};
struct Node* head;
void Insert(int x){
struct Node* temp = (struct Node*)malloc(sizeof(struct Node));
temp->data = x;
temp->next = head;
head = temp;
if(head != NULL)
temp->next = head;
head = temp;
temp->next = NULL;
}
void Print(){
struct Node* temp = head;
printf("List is: ");
while(temp != NULL){
printf("%d", temp->data);
temp = temp->next;
}
printf("\n");
}
int main(){
head = NULL; //empty list
printf("How many numbers?\n");
int n, i;
scanf("%d", &n);
for(int i=0; i < n; i++){
printf("Enter the number\n");
scanf("%d", &x);
Insert(x);
Print();
}
}
```

#3: Post edited by

hamburgersarecool‭ · 2022-01-14T04:40:38Z (almost 3 years ago)

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Can anyone help me, I'm currently learning pointers, this is the code I wrote to try and insert a node at the beginning of the list. However at the part where I included the comment of "error at this line" basically my compiler gave me the error of "In function Insert: Node undeclared".
Why is it so?
```//Inserting a node at the beginning of linked list
#include<stdlib.h>
#include<stdio.h>
struct Node{
int data;
struct Node* next;
};
struct Node* head;
void Insert(int x){
Node* temp = (Node*)malloc(sizeof(struct Node)); //error at this line
temp->data = x;
temp->next = head;
head = temp;
if(head != NULL)
temp->next = head;
head = temp;
}
void Print(){
struct Node* temp = head;
printf("List is: ");
while(temp != NULL){
printf("%d", temp->data);
temp = temp->next;
}
printf("\n");
}
int main(){
head = NULL; //empty list
printf("How many numbers?\n");
int n, i;
scanf("%d", &n);
for(int i=0; i < n; i++){
printf("Enter the number\n");
scanf("%d", &x);
Insert(x);
Print();
}
}
```

Can anyone help me, I'm currently learning pointers, this is the code I wrote to try and insert a node at the beginning of the list. However at the part where I included the comment of "error at this line" basically my compiler gave me the error of "In function Insert: Node undeclared".
Why is it so?
```//Inserting a node at the beginning of linked list
#include<stdlib.h>
#include<stdio.h>
struct Node{
int data;
struct Node* next;
};
struct Node* head;
void Insert(int x){
Node* temp = (Node*)malloc(sizeof(struct Node)); //error at this line
temp->data = x;
temp->next = head;
head = temp;
if(head != NULL)
temp->next = head;
head = temp;
}
void Print(){
struct Node* temp = head;
printf("List is: ");
while(temp != NULL){
printf("%d", temp->data);
temp = temp->next;
}
printf("\n");
}
int main(){
head = NULL; //empty list
printf("How many numbers?\n");
int n, i;
scanf("%d", &n);
for(int i=0; i < n; i++){
printf("Enter the number\n");
scanf("%d", &x);
Insert(x);
Print();
}
}
```
First edit:
My program runs, lets me enter the amount of numbers I want, as well as the numbers, however it prints out only the latest number I entered. What could possibly be the problem? Thanks.
```//Inserting a node at the beginning of linked list
#include<stdlib.h>
#include<stdio.h>
struct Node{
int data;
struct Node* next;
};
struct Node* head;
void Insert(int x){
struct Node* temp = (struct Node*)malloc(sizeof(struct Node));
temp->data = x;
temp->next = head;
head = temp;
if(head != NULL)
temp->next = head;
head = temp;
temp->next = NULL;
}
void Print(){
struct Node* temp = head;
printf("List is: ");
while(temp != NULL){
printf("%d", temp->data);
temp = temp->next;
}
printf("\n");
}
int main(){
head = NULL; //empty list
printf("How many numbers?\n");
int n, i;
scanf("%d", &n);
for(int i=0; i < n; i++){
printf("Enter the number\n");
scanf("%d", &x);
Insert(x);
Print();
}
}
```

#2: Post edited by

hamburgersarecool‭ · 2022-01-13T14:37:16Z (almost 3 years ago)

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Can anyone help me, I'm currently learning pointers, this is the code I wrote to try and insert a node at the beginning of the list. However at the part where I included the comment of "error at this line" basically I don't understand why is there such an error. On my compiler, the error it gave me was "In function Insert: Node undeclared".
```//Inserting a node at the beginning of linked list
#include<stdlib.h>
#include<stdio.h>
struct Node{
int data;
struct Node* next;
};
struct Node* head;
void Insert(int x){
Node* temp = (Node*)malloc(sizeof(struct Node)); //error at this line
temp->data = x; //(*temp).data = x;
temp->next = head;
head = temp;
if(head != NULL)
temp->next = head;
head = temp;
}
void Print(){
struct Node* temp = head;
printf("List is: ");
while(temp != NULL){
printf("%d", temp->data);
temp = temp->next;
}
printf("\n");
}
int main(){
head = NULL; //empty list
printf("How many numbers?\n");
int n, i;
scanf("%d", &n);
for(int i=0; i < n; i++){
printf("Enter the number\n");
scanf("%d", &x);
Insert(x);
Print();
}
}
```

Can anyone help me, I'm currently learning pointers, this is the code I wrote to try and insert a node at the beginning of the list. However at the part where I included the comment of "error at this line" basically my compiler gave me the error of "In function Insert: Node undeclared".
Why is it so?
```//Inserting a node at the beginning of linked list
#include<stdlib.h>
#include<stdio.h>
struct Node{
int data;
struct Node* next;
};
struct Node* head;
void Insert(int x){
Node* temp = (Node*)malloc(sizeof(struct Node)); //error at this line
temp->data = x;
temp->next = head;
head = temp;
if(head != NULL)
temp->next = head;
head = temp;
}
void Print(){
struct Node* temp = head;
printf("List is: ");
while(temp != NULL){
printf("%d", temp->data);
temp = temp->next;
}
printf("\n");
}
int main(){
head = NULL; //empty list
printf("How many numbers?\n");
int n, i;
scanf("%d", &n);
for(int i=0; i < n; i++){
printf("Enter the number\n");
scanf("%d", &x);
Insert(x);
Print();
}
}
```

#1: Initial revision by

hamburgersarecool‭ · 2022-01-13T14:36:29Z (almost 3 years ago)

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Question regarding an error message in my compiler to do with my code on linked list.

Can anyone help me, I'm currently learning pointers, this is the code I wrote to try and insert a node at the beginning of the list. However at the part where I included the comment of "error at this line" basically I don't understand why is there such an error. On my compiler, the error it gave me was "In function Insert: Node undeclared".

```//Inserting a node at the beginning of linked list
#include<stdlib.h>
#include<stdio.h>
struct Node{
    int data;
    struct Node* next; 
};

struct Node* head;
void Insert(int x){ 
    Node* temp = (Node*)malloc(sizeof(struct Node)); //error at this line
    temp->data  = x; //(*temp).data = x;
  
    temp->next = head;
   
    head = temp;

    if(head != NULL)
            temp->next = head; 

    head = temp;
}
void Print(){
    struct Node* temp = head; 
 
    printf("List is: ");
 
    while(temp != NULL){
        printf("%d", temp->data);
        temp = temp->next;
    }
    printf("\n");
}

int main(){
    head = NULL; //empty list
    printf("How many numbers?\n");
    int n, i;
    scanf("%d", &n);
    for(int i=0; i < n; i++){
        printf("Enter the number\n");
        scanf("%d", &x);
        Insert(x); 
        Print();
    }
}
```

c pointers linked-list

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