omarkdev

function setApiVersion(constructor) {
  return class extends constructor {
    version = '0.0.1';
  }
}

@setApiVersion
class Wizard {
}

omarkdev

function logProperty(target: any, key: string) {
  const newKey = `_${key}`;

  Object.defineProperty(target, key, {
    get() {
      console.log(`Get: ${key} => ${this[newKey]}`);
      return this[newKey];
    },
    set(newVal) {
      console.log(`Set: ${key} => ${newVal}`);

omarkdev

function analyze(target: any, key: string) {
  console.log(target, key);
}

class Task {
  @analyze
  public title: string;

  constructor(title: string) {
    this.title = title;

omarkdev

const arr1 = ['a', 'b', 'c', [1, 2, 3]];
const arr1Flatted = arr1.flat();
// ["a", "b", "c", 1, 2, 3]

omarkdev

const arr1 = ['a', ['b', ['c']], 1, [2, [3, [4, [5]]]]];

const arr1Flatted1 = arr1.flat();
// ["a", "b", Array(1), 1, 2, Array(2)]

const arr1Flatted2 = arr1.flat(2);
// ["a", "b", "c", 1, 2, 3, Array(2)]

const arr1FlattedInfinity = arr1.flat(Infinity);
// ["a", "b", "c", 1, 2, 3, 4, 5]

omarkdev

const arr1 = ['a', 'b', , , , ['c', , 1, null, undefined, '', 0]];
const arr1Flatted = arr1.flat();

// ["a", "b", "c", 1, null, undefined, "", 0]

omarkdev

const arr1 = [1, 2, 3, 4];

const arr1FlattedMultipliedByTwo = arr1.flatMap(v => [ v * 2 ]);
// arr1FlattedMultipliedByTwo

omarkdev

const entries = [ ['name', 'Marcos'], ['site', 'omark.dev'], ['twitter', '@omarkdev'] ];

Object.fromEntries(entries);
// {name: "Marcos", site: "omark.dev", twitter: "@omarkdev"}

omarkdev

const message = '     Hello world!     ';

message.trimEnd();
// "     Hello world!"

message.trimStart();
// "Hello world!     "

omarkdev

const symbol1 = Symbol('Awesome');

symbol1.toString();
// "Symbol(Awesome)"