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---
title: "XPathEvaluator: createExpression() method"
short-title: createExpression()
slug: Web/API/XPathEvaluator/createExpression
page-type: web-api-instance-method
browser-compat: api.XPathEvaluator.createExpression
---
{{APIRef("DOM XPath")}}
This method compiles an {{domxref("XPathExpression")}} which can then be used for
(repeated) evaluations of the {{Glossary("XPath")}} expression.
## Syntax
```js-nolint
createExpression(expression)
createExpression(expression, resolver)
```
### Parameters
- `expression`
- : A string representing the XPath expression to be created.
- `resolver` {{optional_inline}}
- : A {{domxref("Node")}}, `null`, or any object implementing the {{domxref("Node/lookupNamespaceURI", "lookupNamespaceURI")}} method. Permits translation of all prefixes, including the `xml` namespace prefix, within the XPath expression into appropriate namespace URIs.
### Return value
A {{domxref("XPathExpression")}} representing the compiled form of the XPath
expression.
### Exceptions
#### INVALID_EXPRESSION_ERR
If the expression is not legal according to the rules of the
`XPathEvaluator`, an {{domxref("XPathException")}} of type
`INVALID_EXPRESSION_ERR` is raised.
#### NAMESPACE_ERR
If the expression contains namespace prefixes which cannot be resolved by the specified
`XPathNSResolver`, a {{domxref("DOMException")}} of type
`NAMESPACE_ERROR` is raised.
## Examples
The following example shows the use of the `evaluate()` method.
### HTML
```html
<div>XPath example</div>
<div>Number of <div>s: <output></output></div>
```
### JavaScript
```js
const xpath = "//div";
const evaluator = new XPathEvaluator();
const expression = evaluator.createExpression(xpath);
const result = expression.evaluate(
document,
XPathResult.ORDERED_NODE_SNAPSHOT_TYPE,
);
document.querySelector("output").textContent = result.snapshotLength;
```
### Result
{{EmbedLiveSample('Examples')}}
## Specifications
{{Specifications}}
## Browser compatibility
{{Compat}}
## See also
- {{DOMxRef("Document.createExpression()")}}
- {{DOMxRef("XPathExpression")}}