Document: createExpression() method

{{APIRef("DOM")}}

This method compiles an {{DOMxRef("XPathExpression")}} which can then be used for (repeated) evaluations.

You must call this method on the same document that you run the expression against.

Syntax

createExpression(xpathText, namespaceURLMapper)

Parameters

• xpathText
  • : A string which is the XPath expression to be compiled.
• namespaceURLMapper
  • : A function which maps a namespace prefix to a namespace URL (or null if none needed).

Return value

{{DOMxRef("XPathExpression")}}

Examples

const xpathExpr = document.createExpression("//div");
const xpathResult = xpathExpr.evaluate(document); // returns an XPathResult object
const nodeContext = document.querySelector("nav");
// Re-using the XPathExpression "xpathExpr"
const otherResult = xpathExpr.evaluate(nodeContext); // returns an XPathResult object

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{DOMxRef("Document.evaluate()")}}
• {{DOMxRef("XPathExpression")}}