Object.getOwnPropertySymbols() - JavaScript 编辑

The Object.getOwnPropertySymbols() method returns an array of all symbol properties found directly upon a given object.

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

Syntax

Object.getOwnPropertySymbols(obj)

Parameters

obj

The object whose symbol properties are to be returned.

Return value

An array of all symbol properties found directly upon the given object.

Description

Similar to Object.getOwnPropertyNames(), you can get all symbol properties of a given object as an array of symbols. Note that Object.getOwnPropertyNames() itself does not contain the symbol properties of an object and only the string properties.

As all objects have no own symbol properties initially, Object.getOwnPropertySymbols() returns an empty array unless you have set symbol properties on your object.

Examples

Using getOwnPropertySymbols

var obj = {};
var a = Symbol('a');
var b = Symbol.for('b');

obj[a] = 'localSymbol';
obj[b] = 'globalSymbol';

var objectSymbols = Object.getOwnPropertySymbols(obj);

console.log(objectSymbols.length); // 2
console.log(objectSymbols);        // [Symbol(a), Symbol(b)]
console.log(objectSymbols[0]);     // Symbol(a)

Specifications

Specification
ECMAScript (ECMA-262) The definition of 'Object.getOwnPropertySymbols' in that specification.

Browser compatibility

BCD tables only load in the browser

See also

• Object.getOwnPropertyNames()
• Symbol