Object.prototype.__lookupGetter__()
Deprecated
This feature has been removed from the Web standards. Though some browsers may still support it, it is in the process of being dropped. Do not use it in old or new projects. Pages or Web apps using it may break at any time.
The __lookupGetter__
method returns the function bound as a getter to the specified property.
Syntax
<var>obj</var>.__lookupGetter__(<var>sprop</var>)
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
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
Specification | Status | Comment |
---|---|---|
ECMAScript 2017 Draft (ECMA-262) The definition of 'Object.prototype.__lookupGetter__()' in that specification. |
Draft | Included in the (normative) annex for additional ECMAScript legacy features for Web browsers (note that the specification codifies what is already in implementations). |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | 11 | (Yes) | (Yes) |
Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | (Yes) | ? | ? | (Yes) |
See also
Object.prototype.__lookupSetter__()
get
operatorObject.getOwnPropertyDescriptor()
andObject.getPrototypeOf()
Object.prototype.__defineGetter__()
Object.prototype.__defineSetter__()
- JS Guide: Defining Getters and Setters
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/javascript/reference/global_objects/object/__lookupgetter__