Inserting a Node in a singly linked list I'm currently writing an "insert" function for a linked list. The code works but I would like to know if there is any way I can improve this code and at the same time covering all the "special" cases.`

private class Node{
    Node next;
    int data;

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

    public Node(){
        this.next = null;
        this.data = 0;
    }}`




public void insert(int data) {
    if(first == null || first.item != data){
        first = new Node(data, first);
    }
    else{
        Node x = first;
        while(x.next != null &amp;&amp; x.next.item != data){
            x.next = new Node(data, x.next);
        }
        x = x.next;
    }
}
public Node(){
      this.next = null;
      this.data = 0;
}



As used, your no-arg constructor can be reduced to Node() {} The default instance values for objects and integers is null and 0 respectively; this is redundant.

In your insert method you refer to item yet it has no reference anywhere, I'm guessing that's supposed to be data but that's conjecture. The same goes for wherever first comes from. I'm guessing the actual linkedList class keeps reference to it, but again without the context this is purely speculation.

I would suggest you ponder why linkedlists are used. When you think of the answer you might realize you want to keep a reference to tail and prev as well.