Object.getOwnPropertySymbols()

Why Object.getOwnPropertySymbols ?

The Object.getOwnPropertySymbols () method returns all the symbol properties that are located on a particular object.

Returns the own symbol properties of an object. The own symbol properties of an object are those that are defined directly on that object, and are not inherited from the object’s prototype.

Syntax:

Object.getOwnPropertySymbols(object);

• object (required):The object that contains the own symbols.
• Return Value: An array that contains the own symbols of the object.

Note:You need to use Object.getOwnPropertySymbols to get the symbol properties of an object. Object.getOwnPropertyNames will not return the symbol properties.

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JavaScript Object.getOwnPropertySymbols Examples

Example 1

        let myObj = {};
        let key = Symbol("description");

        myObj[key] = "data";

        let symbols = Object.getOwnPropertySymbols(myObj);

        console.log(symbols[0].toString())

output:

Symbol(description)

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Example 2

        let myObj = {};
        num1 = Symbol(1);
        num2 = Symbol.for(2);

        let myObjSymbol = Object.getOwnPropertySymbols(myObj);
        console.log(myObjSymbol.length)

output:

0

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Example 3

        let myObj = {};
        let first = Symbol("a");
        let second = Symbol.for("b");

        myObj[first] = "localSymbol";
        myObj[second] = "globalSymbol";

        let objSymbol = Object.getOwnPropertySymbols(myObj);

        console.log(objSymbol.length)

output:

2

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Example 4

        let object1 = {};

        a = Symbol('a');
        b = Symbol.for('b');

        object1[a] = 'Alex';
        object1[b] = 'Rick';

        let objectSymbols = Object.getOwnPropertySymbols(object1);

        console.log(objectSymbols.length);

output:

2

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Example 5

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

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

        let objectSymbols = Object.getOwnPropertySymbols(obj);

        console.log(objectSymbols.length); 
        console.log(objectSymbols);       
        console.log(objectSymbols[0]);   

output:

2
[Symbol(a), Symbol(b)]
Symbol(a)

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Sources:
developer.mozilla.org
www.javatpoint.com
technet.microsoft.com

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Browser Support

Chrome	38
Edge	yes
Firefox	36
Internet Explorer	No
Opera	25
Safari	9
Android webview	38
Chrome for Android	38
Edge mobile	yes
Firefox for Android	36
Opera Android	25