# Circular Singly Linked List - Insert a new node at the end

In this method, a new node is inserted at the end of the circular singly linked list. For example - if the given List is 10->20->30 and a new element 100 is added at the end, the List becomes 10->20->30->100.

Inserting a new node at the end of the circular singly linked list is very easy. First, a new node with given element is created. It is then added at the end of the list by linking the last node and head node to the new node.

The function push_back is created for this purpose. It is a 6-step process.

```void push_back(int newElement) {

//1. allocate node
Node* newNode = new Node();

//2. assign data element
newNode->data = newElement;

//3. assign null to the next of new node
newNode->next = NULL;

//4. Check the list is empty or not,
//   if empty make the new node as head
} else {

//5. Else, traverse to the last node
temp = temp->next;

temp->next = newNode;
}
}
```
```void push_back(struct Node** head_ref, int newElement) {

//1. allocate node
struct Node *newNode, *temp;
newNode = (struct Node*)malloc(sizeof(struct Node));

//2. assign data element
newNode->data = newElement;

//3. assign null to the next of new node
newNode->next = NULL;

//4. Check the list is empty or not,
//   if empty make the new node as head
} else {

//5. Else, traverse to the last node
temp = temp->next;
}

temp->next = newNode;
}
}
```
```def push_back(self, newElement):

#1 & 2 & 3. allocate node, assign data element
#          assign null to the next of new node
newNode = Node(newElement)

#4. Check the list is empty or not,
#   if empty make the new node as head
return
else:

#5. Else, traverse to the last node
temp = temp.next

temp.next = newNode
```
```void push_back(int newElement) {

//1. allocate node
Node newNode = new Node();

//2. assign data element
newNode.data = newElement;

//3. assign null to the next of new node
newNode.next = null;

//4. Check the list is empty or not,
//   if empty make the new node as head
} else {

//5. Else, traverse to the last node
Node temp = new Node();
temp = temp.next;

temp.next = newNode;
}
}
```
```public void push_back(int newElement) {

//1. allocate node
Node newNode = new Node();

//2. assign data element
newNode.data = newElement;

//3. assign null to the next of new node
newNode.next = null;

//4. Check the list is empty or not,
//   if empty make the new node as head
} else {

//5. Else, traverse to the last node
Node temp = new Node();
temp = temp.next;

temp.next = newNode;
}
}
```
```public function push_back(\$newElement) {

//1. allocate node
\$newNode = new Node();

//2. assign data element
\$newNode->data = \$newElement;

//3. assign null to the next of new node
\$newNode->next = null;

//4. Check the list is empty or not,
//   if empty make the new node as head
} else {

//5. Else, traverse to the last node
\$temp = new Node();
\$temp = \$temp->next;
}

\$temp->next = \$newNode;
}
}
```

The below is a complete program that uses above discussed concept to insert new node at the end of the circular singly linked list.

```#include <iostream>
using namespace std;

//node structure
struct Node {
int data;
Node* next;
};

private:
public:
}

//Add new element at the end of the list
void push_back(int newElement) {
Node* newNode = new Node();
newNode->data = newElement;
newNode->next = NULL;
} else {
temp = temp->next;
temp->next = newNode;
}
}

//display the content of the list
void PrintList() {
if(temp != NULL) {
cout<<"The list contains: ";
while(true) {
cout<<temp->data<<" ";
temp = temp->next;
break;
}
cout<<endl;
} else {
cout<<"The list is empty.\n";
}
}
};

// test the code
int main() {

//Add three elements at the end of the list.
MyList.push_back(10);
MyList.push_back(20);
MyList.push_back(30);
MyList.PrintList();

return 0;
}
```

The above code will give the following output:

```The list contains: 10 20 30
```
```#include <stdio.h>
#include <stdlib.h>

//node structure
struct Node {
int data;
struct Node* next;
};

//Add new element at the end of the list
void push_back(struct Node** head_ref, int newElement) {
struct Node *newNode, *temp;
newNode = (struct Node*)malloc(sizeof(struct Node));
newNode->data = newElement;
newNode->next = NULL;
} else {
temp = temp->next;
}
temp->next = newNode;
}
}

//display the content of the list
printf("The list contains: ");
while (1) {
printf("%i ",temp->data);
temp = temp->next;
break;
}
printf("\n");
} else {
printf("The list is empty.\n");
}
}

// test the code
int main() {
struct Node* MyList = NULL;

//Add three elements at the end of the list.
push_back(&MyList, 10);
push_back(&MyList, 20);
push_back(&MyList, 30);
PrintList(MyList);

return 0;
}
```

The above code will give the following output:

```The list contains: 10 20 30
```
```# node structure
class Node:
def __init__(self, data):
self.data = data
self.next = None

def __init__(self):

#Add new element at the end of the list
def push_back(self, newElement):
newNode = Node(newElement)
return
else:
temp = temp.next
temp.next = newNode

#display the content of the list
def PrintList(self):
if(temp != None):
print("The list contains:", end=" ")
while (True):
print(temp.data, end=" ")
temp = temp.next
break
print()
else:
print("The list is empty.")

# test the code

#Add three elements at the end of the list.
MyList.push_back(10)
MyList.push_back(20)
MyList.push_back(30)
MyList.PrintList()
```

The above code will give the following output:

```The list contains: 10 20 30
```
```//node structure
class Node {
int data;
Node next;
};

}

//Add new element at the end of the list
void push_back(int newElement) {
Node newNode = new Node();
newNode.data = newElement;
newNode.next = null;
} else {
Node temp = new Node();
temp = temp.next;
temp.next = newNode;
}
}

//display the content of the list
void PrintList() {
Node temp = new Node();
if(temp != null) {
System.out.print("The list contains: ");
while(true) {
System.out.print(temp.data + " ");
temp = temp.next;
break;
}
System.out.println();
} else {
System.out.println("The list is empty.");
}
}
};

// test the code
public class Implementation {
public static void main(String[] args) {

//Add three elements at the end of the list.
MyList.push_back(10);
MyList.push_back(20);
MyList.push_back(30);
MyList.PrintList();
}
}
```

The above code will give the following output:

```The list contains: 10 20 30
```
```using System;

//node structure
class Node {
public int data;
public Node next;
};

}

//Add new element at the end of the list
public void push_back(int newElement) {
Node newNode = new Node();
newNode.data = newElement;
newNode.next = null;
} else {
Node temp = new Node();
temp = temp.next;
temp.next = newNode;
}
}

//display the content of the list
public void PrintList() {
Node temp = new Node();
if(temp != null) {
Console.Write("The list contains: ");
while(true) {
Console.Write(temp.data + " ");
temp = temp.next;
break;
}
Console.WriteLine();
} else {
Console.WriteLine("The list is empty.");
}
}
};

// test the code
class Implementation {
static void Main(string[] args) {

//Add three elements at the end of the list.
MyList.push_back(10);
MyList.push_back(20);
MyList.push_back(30);
MyList.PrintList();
}
}
```

The above code will give the following output:

```The list contains: 10 20 30
```
```<?php
//node structure
class Node {
public \$data;
public \$next;
}

public function __construct(){
}

//Add new element at the end of the list
public function push_back(\$newElement) {
\$newNode = new Node();
\$newNode->data = \$newElement;
\$newNode->next = null;
} else {
\$temp = new Node();
\$temp = \$temp->next;
}
\$temp->next = \$newNode;
}
}

//display the content of the list
public function PrintList() {
\$temp = new Node();
if(\$temp != null) {
echo "The list contains: ";
while(true) {
echo \$temp->data." ";
\$temp = \$temp->next;
break;
}
echo "\n";
} else {
echo "The list is empty.\n";
}
}
};

// test the code

//Add three elements at the end of the list.
\$MyList->push_back(10);
\$MyList->push_back(20);
\$MyList->push_back(30);
\$MyList->PrintList();
?>
```

The above code will give the following output:

```The list contains: 10 20 30
```

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