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Document: prepend() method

files/en-us/web/api/document/prepend/index.md

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{{APIRef("DOM")}}

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

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

Syntax

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

Parameters

  • param1, …, paramN
    • : A set of {{domxref("Node")}} objects or strings to insert.

Return value

None ({{jsxref("undefined")}}).

Exceptions

  • HierarchyRequestError {{DOMxRef("DOMException")}}
    • : Thrown when the node cannot be inserted at the specified point in the hierarchy.

Examples

Prepending a root element to a document

If you try to prepend an element to an existing HTML document, it might throw a HierarchyRequestError {{domxref("DOMException")}} given a {{HTMLElement("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

{{Specifications}}

Browser compatibility

{{Compat}}

See also

  • {{domxref("Document.append()")}}
  • {{domxref("Element.prepend()")}}