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I have found myself using JavaScript and I ran across childNodes and children properties. I am wondering what the difference between them is. Also is one preferred to the other?

John
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3 Answers3

459

Understand that .children is a property of an Element. 1 Only Elements have .children, and these children are all of type Element. 2

However, .childNodes is a property of Node. .childNodes can contain any node. 3

A concrete example would be:

let el = document.createElement("div");
el.textContent = "foo";

el.childNodes.length === 1; // Contains a Text node child.
el.children.length === 0;   // No Element children.

Most of the time, you want to use .children because generally you don't want to loop over Text or Comment nodes in your DOM manipulation.

If you do want to manipulate Text nodes, you probably want .textContent instead. 4

1. Technically, it is an attribute of ParentNode, a mixin included by Element.
2. They are all elements because .children is a HTMLCollection, which can only contain elements.
3. Similarly, .childNodes can hold any node because it is a NodeList.
4. Or .innerText. See the differences here or here.

MultiplyByZer0
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Raynos
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    Yeah, IE seems to have some problems: http://www.quirksmode.org/dom/w3c_core.html#t71 – Felix Kling Oct 28 '11 at 23:12
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    Actually, children is a property of the parentnode interface, not element. http://usonsci.wordpress.com/2014/09/30/html-children-vs-childnodes/ – victor Sep 30 '14 at 13:37
  • Seems iOS 8.3 (maybe others?) **doesn't support `.children` on XML documents**: http://jsfiddle.net/fbwbjvch/1/ – Saebekassebil May 21 '15 at 10:12
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    Only had trouble with this on Microsoft Edge with XML nodes. It appears Microsoft Edge doesn't like children. That's good, I wouldn't want that browser reproducing. – Dan-Nolan Nov 21 '16 at 02:57
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    Natural follow-up of "element vs. node": http://stackoverflow.com/questions/132564/whats-the-difference-between-an-element-and-a-node-in-xml – user1454265 Jan 27 '17 at 16:30
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Element.children returns only element children, while Node.childNodes returns all node children. Note that elements are nodes, so both are available on elements.

I believe childNodes is more reliable. For example, MDC (linked above) notes that IE only got children right in IE 9. childNodes provides less room for error by browser implementors.

vsync
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Matthew Flaschen
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    Darn, if only this worked on IE 6-8, it would be a dream come true. – Ry- Oct 28 '11 at 23:05
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    @minitech it does work (for some value of work). Apparently `.children` doesn't filter out comment nodes, but it filters out text nodes. – Raynos Oct 28 '11 at 23:16
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    @Raynos: Exactly - same with `.getElementsByTagName('*')`. IE can be so annoying sometimes... – Ry- Oct 28 '11 at 23:17
  • There are shim/polyfill implementations of `children` that support IE. – bill.lee Jan 28 '18 at 07:45
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Good answers so far, I want to only add that you could check the type of a node using nodeType:

yourElement.nodeType

This will give you an integer: (taken from here)

| Value |             Constant             |                          Description                          |  |
|-------|----------------------------------|---------------------------------------------------------------|--|
|    1  | Node.ELEMENT_NODE                | An Element node such as <p> or <div>.                         |  |
|    2  | Node.ATTRIBUTE_NODE              | An Attribute of an Element. The element attributes            |  |
|       |                                  | are no longer implementing the Node interface in              |  |
|       |                                  | DOM4 specification.                                           |  |
|    3  | Node.TEXT_NODE                   | The actual Text of Element or Attr.                           |  |
|    4  | Node.CDATA_SECTION_NODE          | A CDATASection.                                               |  |
|    5  | Node.ENTITY_REFERENCE_NODE       | An XML Entity Reference node. Removed in DOM4 specification.  |  |
|    6  | Node.ENTITY_NODE                 | An XML <!ENTITY ...> node. Removed in DOM4 specification.     |  |
|    7  | Node.PROCESSING_INSTRUCTION_NODE | A ProcessingInstruction of an XML document                    |  |
|       |                                  | such as <?xml-stylesheet ... ?> declaration.                  |  |
|    8  | Node.COMMENT_NODE                | A Comment node.                                               |  |
|    9  | Node.DOCUMENT_NODE               | A Document node.                                              |  |
|   10  | Node.DOCUMENT_TYPE_NODE          | A DocumentType node e.g. <!DOCTYPE html> for HTML5 documents. |  |
|   11  | Node.DOCUMENT_FRAGMENT_NODE      | A DocumentFragment node.                                      |  |
|   12  | Node.NOTATION_NODE               | An XML <!NOTATION ...> node. Removed in DOM4 specification.   |  |

Note that according to Mozilla:

The following constants have been deprecated and should not be used anymore: Node.ATTRIBUTE_NODE, Node.ENTITY_REFERENCE_NODE, Node.ENTITY_NODE, Node.NOTATION_NODE

Csa77
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