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


var 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 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.


The following code traps the delete operator.

var 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

var 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


Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of '[[Delete]]' in that specification.
Standard Initial definition.
ECMAScript Latest Draft (ECMA-262)
The definition of '[[Delete]]' in that specification.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support ? 18 (18) ? ? ?
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support ? ? 18.0 (18) ? ? ?

See also

Document Tags and Contributors

 Contributors to this page: warren-bank, nmve, kdex, eduardoboucas, fscholz, arai
 Last updated by: warren-bank,