Introduction to the use of javascript copy node cloneNode()

cloneNode(a) method accepts a Boolean parameter indicating whether to copy it deeply

true: means to perform deep copy and copy this node and the entire child node tree.

false: shallow copy. Only copy the node itself.

The node copy returned after copy belongs to the document, but does not have a parent node. Unless it is used to add it to the document using appendChild, insertChild(), replaceChild()

The code copy is as follows:

<div id="guoDiv">

<span>1</span>

<span>2</span>

<span>3</span>

</div>

var oDiv = document.getElementById("guoDiv");

var deepList = oDiv.cloneNode(true); //Copy child nodes

alert(deepList.childNodes.length); //3 or 7 (compatibility problem, so the result is different)

var showList = oDiv.cloneNode(false); // Only copy the reference of the current element

alert(showList.childNodes.length); //0