└── linked-list.js


/linked-list.js:
--------------------------------------------------------------------------------
  1 | // const n1 = {
  2 | //     data:100
  3 | // };
  4 | 
  5 | // const n2 = {
  6 | //     data: 200
  7 | // };
  8 | 
  9 | 
 10 | // n1.next = n2;
 11 | 
 12 | // console.log(n1);
 13 | 
 14 | class Node {
 15 |     constructor(data,next=null){
 16 |         this.data=data;
 17 |         this.next =next;
 18 |     }
 19 | }
 20 | 
 21 | class LinkedList {
 22 |     constructor(){
 23 |         this.head = null;
 24 |         this.size =0
 25 |     }
 26 |     //insert first node
 27 |     insertFirst(data){
 28 |         this.head = new Node(data,this.head);
 29 |         this.size++;
 30 |     }
 31 | 
 32 |     //insert last node
 33 |     insertLast(data){
 34 |         let node = new Node(data);
 35 |         let current;
 36 | 
 37 |         //if empty , make head
 38 |         if (!this.head){
 39 |             this.head = node;
 40 |         }else{
 41 |             current=this.head;
 42 | 
 43 | 
 44 |             while(current.next){
 45 |                 current = current.next;
 46 |             } 
 47 | 
 48 |             current.next = node;
 49 |         }
 50 | 
 51 |         this.size++;
 52 | 
 53 |     }
 54 |     
 55 | 
 56 | 
 57 |     //insert at index
 58 | 
 59 |     insertAt( data,index){
 60 |         //if index is out of range
 61 |         if (index > 0 && index > this.size){
 62 |             return;
 63 |         }
 64 | 
 65 |         //if first  index
 66 |         if(index ===0){
 67 |             this.head = new Node(data,this.head);
 68 |             return;
 69 |         }
 70 |         const node = new Node(data);
 71 |         let current,previous;
 72 | 
 73 |         //set current to first 
 74 |         current = this.head;
 75 |         let count=0;
 76 | 
 77 |         while(count<index){
 78 |         previous = current; // Node before index 
 79 |         count++;
 80 |         current = current.next;//Node after index
 81 |         }
 82 | 
 83 |         node.next =current;
 84 |         previous.next=node;
 85 | 
 86 |         this.size++;
 87 |     }
 88 |     //get at index
 89 |     getAt(index){
 90 |         let current = this.head;
 91 |         let count = 0;
 92 | 
 93 |         while (current){
 94 |             if(count == index){
 95 |                 console.log(current.data);
 96 |             }
 97 |             count++;
 98 |             current = current.next;
 99 |         }
100 | 
101 |         return null;
102 |     }
103 | 
104 |     //remove at index
105 | 
106 |     removeAt(index){
107 |         if (index < 0 && index >this.size){
108 |             return;
109 |         }
110 |         let current =this.head;
111 |         let previous;
112 |         let count =0;
113 | 
114 |         // remove first
115 |         if(index ===0){
116 |             this.head =current.next; 
117 |         }else{
118 |             while(count<index){
119 |                 count++;
120 |                 previous =current;
121 |                 current = current.next;
122 |             }
123 |             previous.next = current.next;
124 |         }
125 | 
126 |         this.size--;
127 |     }
128 | 
129 |    
130 | 
131 | 
132 |     //clear list 
133 | 
134 |     clearList(){
135 |         this.head =null;
136 |         this.size = 0;
137 |     }
138 | 
139 |     //print list data
140 | 
141 |     printLlistData(){
142 |         let current = this.head;
143 | 
144 |         while (current){
145 |             console.log(current.data);
146 |             current =current.next;
147 |         }
148 |     }
149 | }
150 | 
151 | const ll = new LinkedList();
152 | 
153 | 
154 | ll.insertFirst(100);
155 | ll.insertFirst(200);
156 | ll.insertFirst(300);
157 | ll.insertLast(400);
158 | // ll.insertAt(506,2);
159 | 
160 | // ll.getAt(2);
161 | 
162 | 
163 | // ll.printLlistData();
164 | console.log(ll.head);


--------------------------------------------------------------------------------