## Boolean treeNode.isFirstNode

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

Judge whether the node is the sibling nodes's first node.

If you use the 'exhide' pack, so this attribute will only support the node which be shown.

Do not initialize or modify it, it is created by the zTree.

### Boolean Format

true means: the node is first node.

false means: the node is not first node.

If the node has been hidden, isFirstNode = false

### Examples of treeNode

#### 1. Judge whether the first selected node is the sibling nodes's first node.

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