Question about Linked Lists

Question

I'm doing an assignment on linked lists and I'm having trouble understanding the insert method. I'm using the one from the book and it works fine, but I don't quite understand it.
public void insert(Object o) {
Node n = new Node(o,current);
if (previous == null)
head = n;
else
previous.next = n;
current = n;
It's my understanding that current is the value that your currently at in the list. Previous is equal to the value before the current. So, previous.next is equal to current. This reasoning won't make the list progress with this code. Can someone tell me what I'm not understanding, or explain how this progresses?

Answer 1

Thanks, that helps alot. Now, I have another question. I need to add and remove nodes from the list. I have it setup where the user can choose what node to delete. It compiles and runs fine, but when I try to delete a node, it doesn't delete it. Doing some troubleshooting, I found that it gets into the for loop, but doesn't do anything with the if/else statement. I put a printline in the if and else part, and it never printed out the statement in the if statement or in the else statement. Here's the code I'm using. getLentgh() is a method I wrote to return an integer value of how many nodes are in the list. I've also tried putting in a printline after the for loop, but still in the try, it didn't print it out.
else if(source == remove) {
String del = JOptionPane.showInputDialog("Enter an integer to remove.");
Node temp = new Node(del,current);
if(del != null){
try{
     for(int c = 0; c < list.getLength(); c++){            
     if(temp.data == current.data){
          list.remove();
          c = list.getLength();
     else{
          list.advance();     
}catch(NullPointerException e){
}