Document: prepend() method

The Document.prepend() method inserts a set of Node objects or strings before the first child of the document. Strings are inserted as equivalent Text nodes.

This method prepends a child to a Document. To prepend to an arbitrary element in the tree, see Element.prepend().

Syntax

js
prepend(param1)
prepend(param1, param2)
prepend(param1, param2, /* …, */ paramN)

Parameters

param1, …, paramN

A set of Node objects or strings to insert.

Return value

None (undefined).

Exceptions

HierarchyRequestError DOMException

Thrown when the node cannot be inserted at the specified point in the hierarchy.

Examples

undefined

Prepending a root element to a document

If you try to prepend an element to an existing HTML document, it might throw a HierarchyRequestError DOMException given a <html> element already exists.

js
let html = document.createElement("html");
document.prepend(html);
// HierarchyRequestError: The operation would yield an incorrect node tree.

If you are creating a new document without any existing element, you can prepend a root HTML element (or a root SVG element):

js
let doc = new Document();
let html = document.createElement("html");
doc.prepend(html);

doc.children; // HTMLCollection [<html>]

Specifications

See also