const nums = [40, 100, 1, 5, 25, 10];
nums.sort();
console.log(nums.join(' '));

class Range {
  #start; #end;
  constructor(start, end) { this.#start = start; this.#end = end; }
  [Symbol.iterator]() {
    let current = this.#start;
    const end = this.#end;
    return {
      next() {
        return current < end
          ? { value: current++, done: false }
          : { value: undefined, done: true };
      },
      [Symbol.iterator]() { return this; }
    };
  }
}

const range = new Range(1, 5);
const arr1 = [...range];
const arr2 = [...range];
const sum = arr1.reduce((a, b) => a + b, 0);
console.log(arr1.join(','), arr2.join(','), sum);

const log = [];

async function a() {
  log.push('a-start');
  await b();
  log.push('a-end');
}

async function b() {
  log.push('b-start');
  await Promise.resolve();
  log.push('b-end');
}

a();
log.push('sync-end');

setTimeout(() => console.log(log.join(',')), 0);

class Counter {
  constructor() {
    this.count = 0;
  }
  increment() {
    this.count++;
    return this.count;
  }
}

const counter = new Counter();
const boundInc = counter.increment.bind(counter);
const rebind = boundInc.bind({ count: 100 });

console.log(boundInc(), rebind(), counter.count);

class Base {
  static count = 0;
  static #secret = 42;
  static {
    Base.count = 10;
  }
  static getSecret() {
    return this.#secret;
  }
}

class Derived extends Base {
  static count = Base.count + 5;
}

let result;
try {
  result = Derived.getSecret();
} catch (e) {
  result = e.constructor.name;
}

console.log(Base.count, Derived.count, result);

class Timer {
  #ticks = 0;
  tick = () => {
    this.#ticks++;
    return this.#ticks;
  };
  reset() {
    this.#ticks = 0;
    return this.#ticks;
  }
}

const t = new Timer();
const { tick, reset } = t;
let result;
try {
  result = reset();
} catch (e) {
  result = e.constructor.name;
}
console.log(tick(), tick(), result);

function createCounters() {
  const counters = [];
  for (let i = 0; i < 3; i++) {
    let count = 0;
    counters.push(() => {
      count += i;
      return count;
    });
  }
  return counters;
}

const counters = createCounters();
const first = counters.map(fn => fn()).join(',');
const second = counters.map(fn => fn()).join(',');
console.log(first, second);