The Node.firstChild
read-only property returns the node's first child in the tree, or null
if the node has no children. If the node is a Document
, it returns the first node in the list of its direct children.
Syntax
var childNode = node.firstChild;
Example
This example demonstrates the use of firstChild
and how whitespace nodes might interfere with using this property.
<p id="para-01"> <span>First span</span> </p> <script> var p01 = document.getElementById('para-01'); console.log(p01.firstChild.nodeName); </script>
In the above, the console will show '#text' because a text node is inserted to maintain the whitespace between the end of the opening <p>
and <span>
tags. Any whitespace will create a #text
node, from a single space to multiple spaces, returns, tabs, and so on.
Another #text
node is inserted between the closing </span>
and </p>
tags.
If this whitespace is removed from the source, the #text nodes are not inserted and the span element becomes the paragraph's first child.
<p id="para-01"><span>First span</span></p> <script> var p01 = document.getElementById('para-01'); console.log(p01.firstChild.nodeName); </script>
Now the console will show 'SPAN'.
To avoid the issue with node.firstChild
returning #text
or #comment
nodes, ParentNode.firstElementChild
can be used to return only the first element node. However, node.firstElementChild
requires a shim for Internet Explorer 9 and earlier.
Specifications
Specification | Status | Comment |
---|---|---|
DOM The definition of 'Node.firstChild' in that specification. |
Living Standard | No change |
Document Object Model (DOM) Level 3 Core Specification The definition of 'Node.firstChild' in that specification. |
Obsolete | No change |
Document Object Model (DOM) Level 2 Core Specification The definition of 'Node.firstChild' in that specification. |
Obsolete | No change |
Document Object Model (DOM) Level 1 Specification The definition of 'Node.firstChild' in that specification. |
Obsolete | Initial definition |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
firstChild | Chrome Full support Yes | Edge Full support 12 | Firefox Full support 1 | IE Full support Yes | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 4 | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes |
Legend
- Full support
- Full support