## Function(treeNode)zTreeObj.getNodeIndex

### Overview[ depends on jquery.ztree.core js ]

Get the node's index in the same level nodes. (start from 0)

Please use zTree object to executing the method.

### Function Parameter Descriptions

#### treeNodeJSON

JSON data object of the node which need to get index.

Please ensure that this data object is an internal node data object in zTree.

#### Return Number

return the index. (start from 0)

If there is no this node, return -1.

### Examples of function

#### 1. Get the first selected node's index in the same level nodes.

    var treeObj = $.fn.zTree.getZTreeObj("tree");
    var nodes = treeObj.getSelectedNodes();
    if (nodes.length>0) {
    	var index = treeObj.getNodeIndex(nodes[0]);
    }