MutationEvent: prevValue property

The prevValue read-only property of the MutationEvent interface returns a string. In DOMAttrModified events, it represents the previous value of the Attr node. In DOMCharacterDataModified events, it contains the previous value of the CharacterData node. In all other cases, returns the empty string ("").

Value

A string.

Examples

element.addEventListener("DOMAttrModified", (event) => {
  console.log(event.previousValue);
});

Specifications

Browser compatibility