What is the “symbol” primitive data type in JavaScript

Question

Can anyone help me why we require a symbol primitive type and what it is used for?

Answer 1

Basically, it comes in use for private and unique keys. No one can able to set the specific map if he/she doesn't share the instance as the property of the symbol. You can take the below code as a reference:

var map = {};

var symbol1 = Symbol("prop");

var symbol2 = Symbol("prop"); // same name, different instance – so it's a different symbol!

map[symbol1] = 1;

map[symbol2] = 2; // doesn't override the previous symbol's value

console.log(map[symbol1] + map[symbol2]); // logs 3

I hope this will help.

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