web api instance method
TreeWalker: firstChild() method
The TreeWalker.firstChild() method moves the current
Node to the first visible child of the current node, and returns
the found child. If no such child exists, it returns null and the current node is not changed.
Syntax
firstChild()
Parameters
None.
Return value
A Node object or null.
Examples
const treeWalker = document.createTreeWalker(
document.body,
NodeFilter.SHOW_ELEMENT,
{
acceptNode(node) {
return NodeFilter.FILTER_ACCEPT;
},
},
false,
);
const node = treeWalker.firstChild(); // returns the first child of the root element, or null if none
Specifications
SpecificationsStandards references are available on the canonical MDN page.
Browser compatibility
Browser compatibilityCompatibility data is available on the canonical MDN page.
See also
- The
TreeWalkerinterface it belongs to.