This feature is deprecated in favor of defining getters using the
object initializer syntax
或
Object.defineProperty()
API. While this feature is widely implemented, it is only described in the
ECMAScript specification
because of legacy usage. This method should not be used since better alternatives exist.
__defineGetter__
method binds an object's property to a function to be called when that property is looked up.
obj.__defineGetter__(prop, func)
prop
A string containing the name of the property to bind to the given function.
func
A function to be bound to a lookup of the specified property.
__defineGetter__
allows a
getter
to be defined on a pre-existing object.
var o = {};
o.__defineGetter__('gimmeFive', function() { return 5; });
console.log(o.gimmeFive); // 5
// Using the get operator
var o = { get gimmeFive() { return 5; } };
console.log(o.gimmeFive); // 5
// Using Object.defineProperty
var o = {};
Object.defineProperty(o, 'gimmeFive', {
get: function() {
return 5;
}
});
console.log(o.gimmeFive); // 5
| 规范 |
|---|
|
ECMAScript (ECMA-262)
The definition of 'Object.prototype.__defineGetter__()' in that specification. |
| Desktop | Mobile | Server | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
__defineGetter__
弃用
|
Chrome 1 | Edge 12 |
Firefox
1
|
IE 11 | Opera 9.5 | Safari 3 | WebView Android 1 | Chrome Android 18 | Firefox Android 4 | Opera Android 10.1 | Safari iOS 1 | Samsung Internet Android 1.0 | nodejs Yes |
完整支持
弃用。不要用于新网站。
见实现注意事项。
Object.prototype.__defineSetter__()
get
operator
Object.defineProperty()
Object.prototype.__lookupGetter__()
Object.prototype.__lookupSetter__()
Object
Object.assign()
Object.create()
Object.defineProperties()
Object.defineProperty()
Object.entries()
Object.freeze()
Object.fromEntries()
Object.getOwnPropertyDescriptor()
Object.getOwnPropertyDescriptors()
Object.getOwnPropertyNames()
Object.getOwnPropertySymbols()
Object.getPrototypeOf()
Object.is()
Object.isExtensible()
Object.isFrozen()
Object.isSealed()
Object.keys()
Object.preventExtensions()
Object.prototype.__defineGetter__()
Object.prototype.__defineSetter__()
Object.prototype.__lookupGetter__()
Object.prototype.__lookupSetter__()
Object.prototype.hasOwnProperty()
Object.prototype.isPrototypeOf()
Object.prototype.propertyIsEnumerable()
Object.prototype.toLocaleString()
Object.prototype.toSource()
Object.prototype.toString()
Object.prototype.valueOf()
Object.seal()
Object.setPrototypeOf()
Object.values()
Function