W3cubDocs

/JavaScript

object.__lookupGetter__

Deprecated
This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

The __lookupGetter__ method returns the function bound as a getter to the specified property.

Syntax

obj.__lookupGetter__(sprop)

Parameters

sprop
A string containing the name of the property whose getter should be returned.

Return value

The function bound as a getter to the specified property.

Description

If a getter has been defined for an object's property, it's not possible to reference the getter function through that property, because that property refers to the return value of that function. __lookupGetter__ can be used to obtain a reference to the getter function.

It is now possible to do this in a standardized way using Object.getOwnPropertyDescriptor() and Object.getPrototypeOf().

Examples

Standard-compliant and non-standard ways to get a property getter

var obj = {
  get foo() {
    return Math.random() > 0.5 ? 'foo' : 'bar';
  }
};


// Non-standard and deprecated way
obj.__lookupGetter__('foo');
// (function() { return Math.random() > 0.5 ? 'foo' : 'bar'; })


// Standard-compliant way
Object.getOwnPropertyDescriptor(obj, "foo").get;
// (function() { return Math.random() > 0.5 ? 'foo' : 'bar'; })

Specifications

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
__lookupGetter__ 1 12 1 11 9.5 3
Mobile
Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
__lookupGetter__ 1 18 4 10.1 1 1.0
Server
Node.js
__lookupGetter__ Yes

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://wiki.developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/__lookupGetter__