The handler.get() method is a trap for getting a property value.

Syntax

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

Parameters

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

target
The target object.
property
The name or Symbol  of the property to get. 
receiver
Either the proxy or an object that inherits from the proxy.

Return value

The get method can return any value.

Description

The handler.get method is a trap for getting a property value.

Interceptions

This trap can intercept these operations:

  • Property access: proxy[foo]and proxy.bar
  • Inherited property access: Object.create(proxy)[foo]
  • Reflect.get()

Invariants

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

  • The value reported for a property must be the same as the value of the corresponding target object property if the target object property is a non-writable, non-configurable data property.
  • The value reported for a property must be undefined if the corresponding target object property is non-configurable accessor property that has undefined as its [[Get]] attribute.

Examples

The following code traps getting a property value.

var p = new Proxy({}, {
  get: function(target, property, receiver) {
    console.log('called: ' + property);
    return 10;
  }
});

console.log(p.a); // "called: a"
                  // 10

The following code violates an invariant.

var obj = {};
Object.defineProperty(obj, 'a', { 
  configurable: false, 
  enumerable: false, 
  value: 10, 
  writable: false 
});

var p = new Proxy(obj, {
  get: function(target, property) {
    return 20;
  }
});

p.a; // TypeError is thrown

Specifications

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

Browser compatibility

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung InternetNode.js
Basic supportChrome 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 49Edge Mobile Full support YesFirefox Android Full support 18Opera Android Full support 36Safari iOS Full support 10Samsung Internet Android Full support 5.0nodejs Full support 6.0.0

Legend

Full support  
Full support
No support  
No support

See also

Document Tags and Contributors

Contributors to this page: alshakero, MarkyMarkMcDonald, wbamberg, fscholz, nmve, kdex, rwaldron, arai
Last updated by: alshakero,