[The spread operator] A simple example to show how it works #spread #operator #typescript

spread-operator.ts

const a = {
  character: 'a',
  description: 'This is a',
  level: 1,
  aUnique: 123
};

const b = {
  description: 'This is b',
  bbb: 'b'
};

const c = {
  test: 'c'
};

const spread = {
  ...a,
  ...b,
  level: c.test
};

console.log(spread);

/**
 * {
 *   character: 'a',
 *   description: 'This is b',
 *   level: 'c',
 *   aUnique: 123,
 *   bbb: 'b'
 * }
 */


// There's something else that's important to remember. If you spread null or undefined it doesn't do anything in the object!

console.log({...null});
// {}

console.log({...undefined});
// {}

// This is applicable if you do something like:
const test = {...myStore.user, loggedIn: true };
// And maybe at that stage myStore.user was actually undefined