# Program To Search An Element In A Singly Linked List

Program To Search An Element In A Singly Linked List on fibonacci, factorial, prime, armstrong, swap, reverse, search, sort, stack, queue, array, linkedlist, tree, graph etc.

## Program to search an element in a singly linked list

### Explanation

In this program, we need to search a node in the given singly linked list.

To solve this problem, we will traverse through the list using a node current. Current points to head and start comparing searched node data with current node data. If they are equal, set the flag to true and print the message along with the position of the searched node.

For, eg. In the above list, a search node says 4 which can be found at the position 4.

### Algorithm

1. Create a class Node which has two attributes: data and next. Next is a pointer to the next node in the list.
2. Create another class SearchLinkedList which has two attributes: head and tail.
1. Create a new node.
2. It first checks, whether the head is equal to null which means the list is empty.
3. If the list is empty, both head and tail will point to a newly added node.
4. If the list is not empty, the new node will be added to end of the list such that tail's next will point to a newly added node. This new node will become the new tail of the list.
4. searchNode() will search for a node in the list:
1. Variable i will keep track of the position of the searched node.
2. The variable flag will store boolean value false.
3. Node current will point to head node.
4. Iterate through the loop by incrementing current to current.next and i to i + 1.
5. Compare each node's data with the searched node. If a match is found, set flag to true.
6. If the flag is true, display the position of the searched node.
7. Else, display the message "Element is not present in the list".
5. display() will display the nodes present in the list:
1. Define a node current which will initially point to head of the list.
2. Traverse through the list till current points to null.
3. Display each node by making current to point to node next to it in each iteration.

### Python

```#Represent a node of the singly linked list
class Node:
def __init__(self,data):
self.data = data;
self.next = None;

def __init__(self):
self.tail = None;

#Create a new node
newNode = Node(data);

#Checks if the list is empty
#If list is empty, both head and tail will point to new node
self.tail = newNode;
else:
#newNode will be added after tail such that tail's next will point to newNode
self.tail.next = newNode;
#newNode will become new tail of the list
self.tail = newNode;

#searchNode() will search for a given node in the list
def searchNode(self, data):
i = 1;
flag = False;

#Checks whether list is empty
print("List is empty");
else:
while(current != None):
#Compares node to be found with each node present in the list
if(current.data == data):
flag = True;
break;
i=i+1;
current = current.next;
if(flag):
print("Element is present in the list at the position : " + str(i));
else:
print("Element is not present in the list");

#Search for node 2 in the list
sList.searchNode(2);
#Search for the node  in the list
sList.searchNode(7);
```

Output:

```Element is present in the list at the position : 2
Element is not present in the list
```

### C

```#include <stdio.h>
#include <stdbool.h>

//Represent a node of the singly linked list
struct node{
int data;
struct node *next;
};

struct node *head, *tail = NULL;

//Create a new node
struct node *newNode = (struct node*)malloc(sizeof(struct node));
newNode->data = data;
newNode->next = NULL;

//Checks if the list is empty
//If list is empty, both head and tail will point to new node
tail = newNode;
}
else {
//newNode will be added after tail such that tail's next will point to newNode
tail->next = newNode;
//newNode will become new tail of the list
tail = newNode;
}
}

//searchNode() will search for a given node in the list
void searchNode(int data) {
int i = 1;
bool flag = false;

//Checks whether list is empty
printf("List is empty \n");
}
else {
while(current != NULL) {
//Compares node to be found with each node present in the list
if(current->data == data) {
flag = true;
break;
}
i++;
current = current->next;
}
}
if(flag)
printf("Element is present in the list at the position: %d\n", i);
else
printf("Element is not present in the list\n");
}

int main()
{

//Search for node 2 in the list
searchNode(2);
//Search for node  in the list
searchNode(7);

return 0;
}
```

Output:

```Element is present in the list at the position : 2
Element is not present in the list
```

### JAVA

```public class SearchLinkedList {

//Represent a node of singly linked list
class Node{
int data;
Node next;

public Node(int data) {
this.data = data;
this.next = null;
}
}

public Node tail = null;

//Create a new node
Node newNode = new Node(data);

//Checks if the list is empty
//If list is empty, both head and tail will point to new node
tail = newNode;
}
else {
//newNode will be added after tail such that tail's next will point to newNode
tail.next = newNode;
//newNode will become new tail of the list
tail = newNode;
}
}

//searchNode() will search for a given node in the list
public void searchNode(int data) {
int i = 1;
boolean flag = false;

//Checks whether list is empty
System.out.println("List is empty");
}
else {
while(current != null) {
//Compares node to be found with each node present in the list
if(current.data == data) {
flag = true;
break;
}
i++;
current = current.next;
}
}
if(flag)
System.out.println("Element is present in the list at the position : " + i);
else
System.out.println("Element is not present in the list");
}

public static void main(String[] args) {

//Search for node 2 in the list
sList.searchNode(2);
//Search for a node  in the list
sList.searchNode(7);
}
}
```

Output:

```Element is present in the list at the position : 2
Element is not present in the list
```

### C#

```using System;

public class CreateList
{
//Represent a node of singly linked list
public class Node<T>{
public T data;
public Node<T> next;

public Node(T value) {
data = value;
next = null;
}
}

public Node<T> tail = null;

//Create a new node
Node<T> newNode = new Node<T>(data);

//Checks if the list is empty
//If list is empty, both head and tail will point to new node
tail = newNode;
}
else {
//newNode will be added after tail such that tail's next will point to newNode
tail.next = newNode;
//newNode will become new tail of the list
tail = newNode;
}
}

//searchNode() will search for a given node in the list
public void searchNode(T data) {
int i = 1;
Boolean flag = false;

//Checks whether list is empty
Console.WriteLine("List is empty");
}
else {
while(current != null) {
//Compares node to be found with each node present in the list
if(current.data.Equals(data)) {
flag = true;
break;
}
i++;
current = current.next;
}
}
if(flag)
Console.WriteLine("Element is present in the list at the position : " + i);
else
Console.WriteLine("Element is not present in the list");
}
}

public static void Main()
{

//Search for node 2 in the list
sList.searchNode(2);
//Search for a node  in the list
sList.searchNode(7);
}
}
```

Output:

```Element is present in the list at the position : 2
Element is not present in the list
```

### PHP

```<!DOCTYPE html>
<html>
<body>
<?php
//Represent a node of singly linked list
class Node{
public \$data;
public \$next;

function __construct(\$data){
\$this->data = \$data;
\$this->next = NULL;
}
}
public \$tail;
function __construct(){
\$this->tail = NULL;
}

//Create a new node
\$newNode = new Node(\$data);

//Checks if the list is empty
//If list is empty, both head and tail will point to new node
\$this->tail = \$newNode;
}
else {
//newNode will be added after tail such that tail's next will point to newNode
\$this->tail->next = \$newNode;
//newNode will become new tail of the list
\$this->tail = \$newNode;
}
}

//searchNode() will search for a given node in the list
function searchNode(\$data) {
\$i = 1;
\$flag = false;

//Checks whether list is empty
print("List is empty<br>");
}
else {
while(\$current != null) {
//Compares node to be found with each node present in the list
if(\$current->data == \$data) {
\$flag = true;
break;
}
\$i++;
\$current = \$current->next;
}
}
if(\$flag)
print("Element is present in the list at the position : " . \$i);
else
print("<br>Element is not present in the list");
}
}

//Search for node 2 in the list
\$sList->searchNode(2);
//Search for node  in the list
\$sList->searchNode(7);
?>
</body>
</html>
```

Output:

```Element is present in the list at the position : 2
Element is not present in the list
```

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