How can i convert this piece of code to a loop?

Question

How can I convert this code to a loop? I have top defined as an instance variable of type NodeString

 NodeString temp1 = top.getNext().getNext().getNext().getNext().getNext();
 NodeString temp2 = top.getNext().getNext().getNext().getNext();
 NodeString temp3 = top.getNext().getNext().getNext();
 NodeString temp4 = top.getNext().getNext();
 NodeString temp5 = top.getNext();
 NodeString temp6 = top;
 result.add(temp1.getData());
 result.add(temp2.getData());
 result.add(temp3.getData());
 result.add(temp4.getData());
 result.add(temp5.getData());
 result.add(temp6.getData());

• shmosel: NodeString next = top; do result.add(0, next.getData()); while ((next = next.getNext()) != null);
• user11064680: @ScaryWombat can you explain further?
• Scary Wombat: Actually @shmosel comment is good enough
• user11064680: @shmosel i made some mods to the piece of code you provided but the result is in reverse. e.g {"a", "b", "c"} gave {"c", "b", "a"}
• shmosel: That's what your code does.

Answer 1

You could build an array and then iterate it backwards. Something like,

NodeString[] arr = { top, arr[0].getNext(), arr[1].getNext(), 
 arr[3].getNext(), arr[4].getNext(), arr[5].getNext() };
for (int i = arr.length - 1; i >= 0; i--) {
 result.add(arr[i].getData());
}

• user11064680: i have the array i want to clone in the main function
• Elliott Frisch: @scott The code I have posted here is equivalent to the code in your question.
• Scary Wombat: @ElliottFrisch Is the iteration order necessary?
• Elliott Frisch: @ScaryWombat No, but you'd need to build the array in reverse (assuming it's relevant to op's original code).
• user11064680: the code posted in the comment by @shmosel worked okay for me, with some modifications. I didn't want to pass an array as a parameter.

Answer 2

Solution using recursion.

List func(NodeString top,List result){
 if(top==null){
 return result;
 }else{
 result = func(top.next,result);
 result.add(top.data);
 }
 return result;
}

---

further you can func call like this:

List result = func(top, new ArrayList());

Answer 3

You can use the following method to get the nodes list. You need to send the top node to the method and it will return the nodes list. This method is written to make sure the exact logic you have mentioned, which is to add the top node to the bottom and the child nodes to the top.

 private List<NodeString> generateNodeList(NodeString topNode) {
 List<NodeString> result = new LinkedList<>();
 NodeString currentNode = topNode;
 while(currentNode != null) {
 result.add(0, currentNode);
 currentNode = currentNode.getData();
 }
 return result;
 }