Simple JAVA approach

public static Node insert(Node head,int data) {

    if(head==null){
        head = new Node(data);
    }
    else{
        Node start = head;
        while(start.next != null){
        start = start.next;
    }

    Node newNode = new Node(data);
    start.next = newNode;
    }
    return head;
}