The handler.deleteProperty() method is a trap for the delete operator.


const p = new Proxy(target, {
  deleteProperty: function(target, property) {


The following parameters are passed to the deleteProperty() method. this is bound to the handler.

The target object.
The name or Symbol of the property to delete.

Return value

The deleteProperty() method must return a Boolean indicating whether or not the property has been successfully deleted.


The handler.deleteProperty() method is a trap for the delete operator.


This trap can intercept these operations:


If the following invariants are violated, the proxy will throw a TypeError:

  • A property cannot be deleted, if it exists as a non-configurable own property of the target object.


Trapping the delete operator

The following code traps the delete operator.

const p = new Proxy({}, {
  deleteProperty: function(target, prop) {
    if (prop in target){
      delete target[prop]
      console.log('property removed: ' + prop)
      return true
    else {
      console.log('property not found: ' + prop)
      return false

let result

p.a = 10
console.log('a' in p)  // true

result = delete p.a    // "property removed: a"
console.log(result)    // true
console.log('a' in p)  // false

result = delete p.a    // "property not found: a"
console.log(result)    // false


ECMAScript (ECMA-262)
The definition of '[[Delete]]' in that specification.

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
deletePropertyChrome Full support 49Edge Full support 12Firefox Full support 18IE No support NoOpera Full support 36Safari Full support 10WebView Android Full support 49Chrome Android Full support 49Firefox Android Full support 18Opera Android Full support 36Safari iOS Full support 10Samsung Internet Android Full support 5.0nodejs Full support 6.0.0


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See also