React create constants file

Question

How to create constants file like: key - value in ReactJs,

ACTION_INVALID = \"This action is invalid!\"

and to use that in other components

Answer 1

One way to do that (not so different from other answers though) is to create a bare constants.js file and add your constants there.

module.exports = Object.freeze({
  ACTION_INVALID: 'This action is invalid',
  ACTION_VALID: 'Some other action',
});

Then you can import it

import ConstantsList from './constants';

and use

console.log(ConstantsList.ACTION_INVALID)

As the name suggests, Object.freeze() freezes objects and stops anyone from changing the values. Please note: if the values are objects themselves they are changeable (unless they are also frozen)