a simple example of linked list

working sample code->https://stackblitz.com/edit/typescript-mzgnay

operation done:-
add item is a linked list->at last
add item at starting
remove item by value
remove item by index
insert item before
insert item after
reverse linked list


code:-

//Linked list ---------------------------------------------------

//create a class which holds data and address of next class

//newNode

class newNode

{

//data which can store any type of data but right now i am not handling array and object data type only string or number

data:any;

next:newNode;

}

class LinkedList

{

//Head store first node in linked list

Head:newNode=null;

//last node in the linked list

Tail:newNode=null;

//length of linked list

len:number=0;

/*

push a node at last of linked list

*/

public push(data:any)//push data

{

//create a new node---step1

var node=new newNode();

//pass data to node---step2

node.data = data;

//if there is only one node make that node head and tail---step3

if(this.Head===null)

{

this.Head=node;

this.Tail=node;

}

else

{

//fill the tail with new node

//like---> node[data,node]->node[data,node]->node[data,node] so on...

//where second parameter holding address or link to the next node

this.Tail.next = node;

this.Tail = node;

}

//increment index by one

this.len +=1;

}

/*display the whole linked list...............................................*/

public list()

{

//move head to a new node

let node=this.Head;

//loop the node utill you found a null node

while(node !=null)

{

console.log(node.data+"----->");

node=node.next;

}

}

/*reverse the whole linked list................................................*/

public reverse()

{

//if there is only one node in the linked list==>

if(this.Head.next==null)

{

console.warn("i don't know how to reverse one item in linked list");

return;

}

//set curr_head=head.next node

let curr_head=this.Head.next;

//and rev_head to the head

let rev_head=this.Head;

//make rev_head to null

rev_head.next=null;

while(curr_head)

{

let temp=curr_head;

curr_head=curr_head.next;

temp.next=rev_head;

rev_head=temp;

}

this.Head=rev_head;

let currentNode=rev_head;

while(currentNode!=null)

{

console.log(currentNode.data);

currentNode=currentNode.next;

}

}

//delete by value not applied for array and object

public deleteByValue(value)

{

let node=this.Head;

let oldnode=null;

while(node !=null)

{

if(node.data===value)

{

let temp=node;

node=null;

oldnode.next=temp.next;

node=oldnode.next.next;

this.len -=1;

}

oldnode=node;

node=node.next;

}

}

//delete by index

public deleteByIndex(index)

{

let node=this.Head;

let oldnode=null;

let fetchedIndex=0;

while(node !=null)

{

if(index===fetchedIndex)

{

let temp=node;

node=null;

oldnode.next=temp.next;

node=oldnode.next.next;

this.len -=1;

}

oldnode=node;

node=node.next;

fetchedIndex+=1;

}

}

//append at start

public append(data)

{

var node=new newNode();

node.data = data;

if(this.Head===null)

{

this.Head=node;

this.Tail=node;

}else

{

let temp=this.Head;

this.Head=node;

this.Head.next = temp;

}

this.len +=1;

}

//insert at a given position Before

public insertByPositionBefore(data:any,index:number)

{

let startIndex=0;

let node=this.Head;

let previous=null;

while(node !=null)

{

if(startIndex===index)

{

let temp=node;

let newDataWithNode=new newNode();

newDataWithNode.data=data

newDataWithNode.next=temp;

if(previous!=null)

{

previous.next=newDataWithNode;

}

this.len +=1;

}

previous=node;

node=node.next;

startIndex+=1;

}

}

//insert by value Before no object and array

public insertByValueBefore(data:any,searchData:any)

{

let node=this.Head;

let previous=null;

while(node !=null)

{

if(node.data===searchData)

{

let temp=node;

let newDataWithNode=new newNode();

newDataWithNode.data=data

newDataWithNode.next=temp;

if(previous!=null)

{

previous.next=newDataWithNode;

}

this.len +=1;

}

previous=node;

node=node.next;

}

}

//insert at a given position after

public insertByPositionAfter(data:any,index:number)

{

let startIndex=0;

let node=this.Head;

while(node !=null)

{

if(startIndex===index)

{

let temp=node;

let newDataWithNode=new newNode();

newDataWithNode.data=data

newDataWithNode.next=node.next

node.next=newDataWithNode;

this.len +=1;

}

startIndex+=1;

node=node.next;

}

}

//insert by value after no object and array

public insertByValueAfter(data:any,searchData:any)

{

let node=this.Head;

while(node !=null)

{

if(node.data===searchData)

{

let temp=node;

let newDataWithNode=new newNode();

newDataWithNode.data=data

newDataWithNode.next=node.next

node.next=newDataWithNode;

this.len +=1;

}

node=node.next;

}

}

//push a item at last------------------>>>>>

public length()

{

if(length<0)

{

console.warn("linked list is empty.....");

}

return this.len;

}

}

var mylist=new LinkedList();

mylist.push("iphone")

mylist.push("ipad")

mylist.insertByValueAfter("computer","iphone");

mylist.insertByValueAfter("computer next","computer");

mylist.insertByValueBefore("computer next next next","computer next");

mylist.insertByPositionAfter("this is a new computer1",2);

mylist.insertByPositionBefore("this is a new computer2",2);

mylist.append("add me at first");

mylist.push("add me at last");

console.log("1**************---------->display whole list")

mylist.list();

console.log("1**************---------->length of list")

console.log(mylist.length());

console.log("1**************---------->reverse the list")

mylist.reverse();

console.log("1**************---------->length of list")

console.log(mylist.length());

mylist.deleteByValue("computer");

mylist.deleteByValue("computer next next next");

mylist.deleteByIndex(1);

console.log("2**************---------->display whole list scond time")

mylist.list();

console.log("**************---------->length of list")

console.log("2changed length",mylist.length());