JavaScript .getOwnPropertySymbols()

The .getOwnPropertySymbols() method is a static method that returns an array of all symbol properties found directly upon a given object. If the object initially has no symbol properties, .getOwnPropertySymbols() returns an empty array.

Note: .getOwnPropertySymbols() method itself does not contain the symbol properties of an object and only the string properties.

Syntax

Object.getOwnPropertySymbols(object_name)

• object_name: The name of an object whose symbol properties are to be returned.

Examples

Example 1

In the following code, [Symbol('😊')] and [Symbol('^O^')] will create symbol properties for the Electronic_Devices object. The localSymbol and globalSymbol values specify that these symbols are created with the Symbol functions as Symbol() and Symbol.for() directly within the scope of the Electronic_Devices object without any global registration. They are not implying that those symbols are truly global in the sense of being accessible everywhere. Object.getOwnPropertySymbols(object_name) will return an array of all symbol properties that have been found:

var Electronic_Devices = {
  group1: ['Fridge', 'Microwave', 'Rice Cooker', 'Washing Machine'],
  //add symbol
  [Symbol('😊')]: 'localSymbol',
  [Symbol('^O^')]: 'globalSymbol',
};
console.log(Object.getOwnPropertySymbols(Electronic_Devices));

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The above example will return the following output:

[ Symbol(😊), Symbol(^O^) ]

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Example 2

In the following code, Symbol() and Symbol.for() will add symbol properties to the Electronic_Devices object. Next, the program will output the Electronic_Devices object into the console. Then, the objectSymbols variable that is assigned to Object.getOwnPropertySymbols(object_name) will be used to return the length of an array of all symbol properties that have been found, the array itself, and the first element in the array:

var Electronic_Devices = {
  group1: ['Fridge', 'Microwave', 'Rice Cooker', 'Washing Machine'],
};
var symbol_1 = Symbol('😊');
var symbol_2 = Symbol.for('^O^');

Electronic_Devices[symbol_1] = 'localSymbol';
Electronic_Devices[symbol_2] = 'globalSymbol';

var objectSymbols = Object.getOwnPropertySymbols(Electronic_Devices);

console.log(Electronic_Devices + '\n');
console.log(objectSymbols.length + '\n');
console.log(objectSymbols);
console.log(objectSymbols[0]);

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The above example will return the following output:

{
  group1: ['Fridge', 'Microwave', 'Rice Cooker', 'Washing Machine'],
  [Symbol(😊)]: 'localSymbol',
  [Symbol(^O^)]: 'globalSymbol'
}

2

[Symbol(😊), Symbol(^O^)]
Symbol(😊)

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