In this method I keep getting a return value of One even after I add more nodes

问题

Got a quick question, this is part of a linked list. It determines what the size of the list is, it doesnt work very well at the moment because it keeps returning a 1 even after I add more nodes.

public int size(){
ListNode currentNode = null;
ListNode previousNode = null;
int numberOfNodes = 0;

if (head == null) return 0;

previousNode = head;
currentNode = head.next;

numberOfNodes++;

while (currentNode != null){
    previousNode = currentNode;
    currentNode = currentNode.next;
    numberOfNodes++;
}
return numberOfNodes;

}

回答1:

If the addNode function is as the one in here then you have an error:

Last line should be

    previousNode.next = newNode;

instead of

    newNode = previousNode.next;

回答2:

Too much clutter in this code, try the following:

public int size() {
  int numberOfNodes = 0;
  ListNode currentNode = head;
  while (currentNode != null){
    numberOfNodes++;
    currentNode = currentNode.next;
  }
  return numberOfNodes;
}

来源：https://stackoverflow.com/questions/6558658/in-this-method-i-keep-getting-a-return-value-of-one-even-after-i-add-more-nodes