LinkList for beginner - linked-list

Question

public class Node {
int item;
Node next;
public Node() {
item = 0;
this.next = null;
}
public Node(int c) {
item = c;
next = null;
}
public Node(int c, Node next) {
item = c;
this.next = next;
}
}
public class List {
Node head;
Node tail;
int size;
public boolean isEmpty(){
return head == null;
}
public int size(){
return size;
}
public void addF(int i){
head = new Node(i, head);
size++;
}
public void addE(int i){
if(head == null){
Node s = new Node(i);
tail = head;
}else{
Node s = head;
while(s.next != null){
s = s.next;
}
s.next = new Node(i);
size++;
}
}
public static void main(String[] args){
List l = new List();
l.addF(55);
l.addF(56);
l.addF(57);
l.addE(54);
l.addE(53);
System.out.println(l.toString());
}
public String toString() {
String result = "[ ";
Node current = head;
while (current != null) {
result = result + current.item + " ";
current = current.next;
}
return result + "]";
}
}
Can anyone explain how the method addE() about else statement in detail for me please? I understand if statement but not else. I'm trying to understand it better. Thank you!!!

Answer 1

I think the code should be as follows:-
public void addE(int i){
if(head == null){
Node s = new Node(i);
head=s; //If the link list is empty then the first element(node) is the head
}else{
while(s.next != null){ //Traverse the entire linked list until you raech the tail
s = s.next;
}
s.next = new Node(i);//add the new node
size++;
}
}