0.2.2 • Published 5 months ago
@stdlib/utils-inherited-keys v0.2.2
inheritedKeys
Return an array of an object's inherited enumerable property names.
Installation
npm install @stdlib/utils-inherited-keys
Usage
var inheritedKeys = require( '@stdlib/utils-inherited-keys' );
inheritedKeys( obj[, level] )
Returns an array
of an object's inherited enumerable property names.
function Foo() {
this.a = 'b';
return this;
}
Foo.prototype.beep = 'boop';
var f = new Foo();
var keys = inheritedKeys( f );
// returns [ 'beep' ]
By default, the function walks an object's entire prototype chain. To limit the inheritance level, provide a level
argument.
var inherit = require( '@stdlib/utils-inherit' );
function Bar() {
return this;
}
Bar.prototype.boop = 'beep';
function Foo() {
Bar.call( this );
this.a = 'b';
return this;
}
inherit( Foo, Bar );
Foo.prototype.beep = 'boop';
var f = new Foo();
var keys = inheritedKeys( f, 1 );
// returns [ 'beep' ]
Notes
- Name order is not guaranteed, as
object
key enumeration is not specified according to the ECMAScript specification. In practice, however, most engines use insertion order to sort anobject
's keys, thus allowing for deterministic extraction.
Examples
var defineProperty = require( '@stdlib/utils-define-property' );
var inheritedKeys = require( '@stdlib/utils-inherited-keys' );
function Foo() {
this.beep = 'boop';
this.a = {
'b': 'c'
};
defineProperty( this, 'baz', {
'configurable': false,
'enumerable': false,
'writable': true,
'value': 'qux'
});
return this;
}
Foo.prototype.foo = [ 'bar' ];
defineProperty( Foo.prototype, 'bip', {
'configurable': false,
'enumerable': false,
'writable': false,
'value': 'bop'
});
var obj = new Foo();
var keys = inheritedKeys( obj );
console.log( keys );
// => [ 'foo' ]
See Also
@stdlib/utils-keys
: return an array of an object's own enumerable property names.@stdlib/utils-keys-in
: return an array of an object's own and inherited enumerable property names.@stdlib/utils-inherited-property-names
: return an array of an object's inherited enumerable and non-enumerable property names.@stdlib/utils-inherited-property-symbols
: return an array of an object's inherited symbol properties.
Notice
This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.
For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.
Community
License
See LICENSE.
Copyright
Copyright © 2016-2024. The Stdlib Authors.