For Loop error that I need a variable here not value

Question

I want to insert nodes which are fetched from other part of the program into a NodeList.

static void NodeCheck(Node node)
{
    NodeList NodeArray = null;
    for(int i=0;NodeArray.getLength()<=i;i++)
    {
        NodeArray.item(i)=node;
    }
}

here it goes, the NetBeans gives me the error that I need a variable here not value. what would be the solution?

EDIT: Ok let change to this

NodeList NodeArray = null;

        NodeArray.item(0)=node;

there is no iteration and still same error,,,,

EDIT NO.2: let me make my question more clear, how can I insert nodes (single nodes) into something like an array? ant idea? the reason to do this, is to compare them with each other to see weather they are same or different.

The solution might be reading some book. That code do not have sense even if the NodeArray were initialized. — Damian Leszczyński - Vash, Nov 29 '11 at 10:15
Gearóid is right. then, your logic has `i>=length`. Hope you mean what you have written in that logic. usually it will be `i<=length`. — Naveen Babu, Nov 29 '11 at 10:35
I suggest reading up java language properly. The code has some serious errors . — Gautam, Nov 29 '11 at 13:52

score 2 · Accepted Answer · answered Nov 29 '11 at 10:15

2

This line will set the NodeArray to null.

  NodeList `NodeArray` = null;

In the next line you're trying to call a method on this NodeArray which is null, this can't work.

  NodeArray.getLength()

You have to initialize the NodeArray properly to a non null value.

answered Nov 29 '11 at 10:15

flash

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The code doesn't even compile, so the runtime NPE isn't even thrown yet – Vivien Barousse Nov 29 '11 at 10:18

score 0 · Answer 2 · answered Nov 29 '11 at 10:16

0

You cannot insert into org.w3c.dom.NodeList. Use appropriate element methods e.g. org.w3c.dom.Node#appendChild.

answered Nov 29 '11 at 10:16

kan

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score 0 · Answer 3 · answered Nov 29 '11 at 10:16

0

It's possibly nullPointerException because NodeArray is null when you call length() method for it.

answered Nov 29 '11 at 10:16

shift66

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score 0 · Answer 4 · answered Nov 29 '11 at 10:17

0

i think that the first problem you have is that the NodeArray is null, and you cant acces to a property of a null element... try doing something like this:

NodeList NodeArray = new NodeList();

answered Nov 29 '11 at 10:17

melli-182

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org.w3c.dom.NodeList is an interface. You're code won't work. – flash Nov 29 '11 at 10:19
Oh i thought that he created her own Class called NodeList (there was none import statement)... If he is using the interface... the problem is different... – melli-182 Nov 29 '11 at 10:22

Julien DAUPHANT · Answer 5 · 2011-11-29T12:37:07.330

0

You have to assign "nodeArray", also you get a NullPointerException on the line "NodeArray.getLength()". I also recommends to start variables and functions names by lowercase (by convention).

static Node rootNode; 
static void nodeCheck(Node node)
{
    NodeList nodeArray = rootNode.getChildNodes(); // if rootNode==null -> NullPointerException
    for(int i=0;nodeArray.getLength()<=i;i++) // if nodeArray==null -> NullPointerException
    {
        //replace child of rootNode by node
        rootNode.replaceChild(node,nodeArray.item(i));           
    }
    //add child to rootNode
    rootNode.appendChild(node); 
}

Best regards, Julien

edited Nov 29 '11 at 12:37

answered Nov 29 '11 at 10:18

Julien DAUPHANT

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1. `NodeList` is an interface. 2. `nodeArray.item(i)=node` won't work too, because it is a getter method. – flash Nov 29 '11 at 10:24
Thanks @flash , I don't know the interface, I just view the NullPointerException. I correct my answer. – Julien DAUPHANT Nov 29 '11 at 12:30

score 0 · Answer 6 · edited Nov 14 '12 at 00:24

0

When you have nothing there and you are iterating it, it will result null pointer.

The NodeList should be initialized before you iterate.

edited Nov 14 '12 at 00:24

Mxyk

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answered Nov 29 '11 at 10:22

Tushar Agarwal

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For Loop error that I need a variable here not value

6 Answers6