How to delete a Node from Linked List in java

How to delete a Node from Linked List in java

LinkedList  

In our earlier tutorials we have seen lot of Linked List related questions and programs. On similar stage another question is how to delete a Node from a Linked List. Same way lets create a Linked List and try to delete a node from it with simple Java code.

class NODE {

 int data;
 NODE next = null;

 public NODE(int data) {
  this.data = data;
 }
}

public class DeleteLLNode {
 
 public static void main(String[] args) {

  int array[] = new int[] { 11, 12, 13, 14, 15, 16, 17, 18 };
  int deleteNode = 15;
  
  DeleteLLNode obj = new DeleteLLNode();

  // Create linkedlist based all array values
  NODE start = obj.createLinkedList(array);
  
  // Print all node values before delete
  obj.printLinkedList(start);
  
  start = obj.deleteNode(start, deleteNode);

  // Print all node values after delete
  obj.printLinkedList(start);
 }

 /*
  * Create LinkedList and return the start pointer/node
  */
 public NODE createLinkedList(int[] array) {

  NODE start = null;
  NODE tmp = null;

  for (int i : array) {

   tmp = new NODE(i);

   if (start == null) {
    start = tmp;
   } else {
    NODE mover = start;
    while (mover.next != null) {
     mover = mover.next;
    }
    mover.next = tmp;
   }
  }
  return start;
 }
 
 /*
  *  Print all linked list node values 
  */
 public void printLinkedList(NODE start) {
  System.out.print("Linked List: ");
  while(start != null) {
   System.out.print(start.data +", ");
   start = start.next;
  }
  System.out.println();
 }

 /*
  * Delete Linked List node 
  */
 public NODE deleteNode(NODE start, int val) {
  NODE tmp = start;
  
  // If its first node to delete
  if(tmp != null && tmp.data == val) {
   start = start.next;
   return start;
  }
  
  NODE previous = null;
  while(tmp != null) {
   if(tmp.data == val) {
    previous.next = tmp.next;
   }
   previous = tmp;
   tmp = tmp.next;
  }
  return start;
 }
}

OUTPUT:

Linked List: 11, 12, 13, 14, 15, 16, 17, 18, 
Linked List: 11, 12, 13, 14, 16, 17, 18,