Javascript

What are Javascript Symbols?

The symbol returns a unique value every time.

The data type symbol is a primitive data type in ES6. Every symbol returns a unique identity.

Note

symbol() is a factory function in javascript

Demo

Syntax

WriteSymbol() in javascript

let symbol= Symbol();
let symbol2= Symbol('Rajdeep singh');
let symbol3= Symbol('Javascript');

When creating a new symbol each time in javascript. So every time, a symbol provides its own unique identity.

Symbol() === Symbol() // false

use new operator makes a shows TypeError in Browser.

let Error= new Symbol() // show TypeError

You are interested to see symbols are primitive data types, so you use the typeof operator. Check data type.

typeof Symbol()  // return "symbol"

Properties

1. Symbol.length
2. Symbol.prototype

Symbol.length:

Symbol.length // allways return 0
Symbol("Rajdeep").length); // return undefined

Symbol.prototype:

Symbol.prototype // return Symbol{}
Symbol("Rajdeep").toString() // return Symbol(Rajdeep)
Symbol("Singh").valueOf()  // return Symbol(Singh)

Read More On Medium

Reference

• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol
• https://www.freecodecamp.org/news/how-did-i-miss-javascript-symbols-c1f1c0e1874a/

Play Demo

Conclusion

The symbol is useful when you work with a unique identity. you are using the symbol in an object and using it in react.js as key || keys props.

Lots of things you try, but for me, I never use them in real life.

Please tell me in the comment box if you have any queries, mistakes, or suggestions.

Contact me:

• https://www.officialrajdeepsingh.dev/
• [email protected]