DocumentType: systemId property

The read-only systemId property of the DocumentType returns the URL of the associated DTD.

For synthetic DocumentType, this property reflects the value given in parameter to createDocumentType().

Value

A string.

Examples

const docType = document.implementation.createDocumentType(
  "svg",
  "",
  "http://www.w3.org/2000/svg",
);

console.log(docType.systemId); // Displays "http://www.w3.org/2000/svg"

Specifications

Browser compatibility