Object.prototype.__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
__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 compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
__lookupGetter__ |
1 |
12 |
1 |
11 |
9.5 |
3 |
1 |
18 |
4 |
10.1 |
1 |
1.0 |
See also
- A polyfill of
Object.prototype.__lookupGetter__
is available incore-js
Object.prototype.__lookupSetter__()
-
get
operator -
Object.getOwnPropertyDescriptor()
andObject.getPrototypeOf()
Object.prototype.__defineGetter__()
Object.prototype.__defineSetter__()
- JS Guide: Defining Getters and Setters
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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/__lookupGetter__