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

Syntax

var p = new Proxy(target, {
  deleteProperty: function(target, property) {
  }
});

Parameters

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

target
The target object.
property
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.

Description

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

Interceptions

This trap can intercept these operations:

Invariants

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.

Examples

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

Specifications

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.
Living Standard  

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support491218 No3610
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidIE mobileOpera AndroidiOS Safari
Basic support4949 Yes18 No3610

See also

Document Tags and Contributors

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