JavaScript

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A resourceful newsletter featuring the latest and most important news, articles, books and updates in the world of #javascript 🚀 Don't miss our Quizzes! Let's chat: @nairihar

India13 551 Technologies & Applications4 384...

📈 Analytical overview of Telegram channel JavaScript

Channel JavaScript (@javascript) in the English language segment is an active participant. Currently, the community unites 31 443 subscribers, ranking 4 384 in the Technologies & Applications category and 13 551 in the India region.

📊 Audience metrics and dynamics

Since its creation on невідомо, the project has demonstrated rapid growth, gathering an audience of 31 443 subscribers.

According to the latest data from 13 June, 2026, the channel demonstrates stable activity. Although there has been a change in the number of participants by -193 over the last 30 days and by 21 over the last 24 hours, overall reach remains high.

Verification status: Not verified
Engagement rate (ER): The average audience engagement rate is 6.27%. Within the first 24 hours after publication, content typically collects 2.53% reactions from the total number of subscribers.
Post reach: On average, each post receives 1 972 views. Within the first day, a publication typically gains 796 views.
Reactions and interaction: The audience actively supports content: the average number of reactions per post is 7.
Thematic interests: Content is focused on key topics such as javascript, console.log(gen.next().value, processdata, remix, acc.

📝 Description and content policy

The author describes the resource as a platform for expressing subjective opinions:
“A resourceful newsletter featuring the latest and most important news, articles, books and updates in the world of #javascript 🚀 Don't miss our Quizzes! Let's chat: @nairihar”

Thanks to the high frequency of updates (latest data received on 14 June, 2026), the channel maintains relevance and a high level of publication reach. Analytics show that the audience actively interacts with content, making it an important point of influence in the Technologies & Applications category.

31 443

Subscribers

+2124 hours

-537 days

-19330 days

1 972

Post views

~ 79624 hours

~ 1 05148 hours

6.27%

Engagement rate

~ 2

Posts per day

Ads index

beta

Posts Archive

31 439

CHALLENGE

const target = { name: 'Sarah', age: 25 };
const handler = {
  get(obj, prop) {
    if (prop === 'toString') {
      return () => `Person: ${obj.name}`;
    }
    return Reflect.get(obj, prop);
  },
  has(obj, prop) {
    return prop !== 'age' && Reflect.has(obj, prop);
  }
};
const proxy = new Proxy(target, handler);
console.log(proxy.name);
console.log('age' in proxy);
console.log(proxy.toString());

31 439

What is the output?

Anonymous voting

31 439

CHALLENGE

class StateMachine {
  constructor() {
    this.state = 'idle';
    this.transitions = {
      idle: { start: 'running', reset: 'idle' },
      running: { pause: 'paused', stop: 'stopped' },
      paused: { resume: 'running', stop: 'stopped' },
      stopped: { reset: 'idle' }
    };
  }
  
  transition(action) {
    const nextState = this.transitions[this.state]?.[action];
    if (nextState) {
      this.state = nextState;
      return true;
    }
    return false;
  }
}

const sm = new StateMachine();
console.log(sm.transition('start'));
console.log(sm.state);
console.log(sm.transition('reset'));
console.log(sm.state);

31 439

😆

31 439

What is the output?

Anonymous voting

31 439

CHALLENGE

class ValidationError extends Error {
  constructor(message, code) {
    super(message);
    this.name = 'ValidationError';
    this.code = code;
  }
}

function processData(data) {
  try {
    if (!data) throw new ValidationError('Data required', 'MISSING_DATA');
    return data.toUpperCase();
  } catch (error) {
    if (error instanceof ValidationError) {
      console.log(`${error.name}: ${error.message} (${error.code})`);
    } else {
      console.log(`Unexpected error: ${error.message}`);
    }
  }
}

processData(null);
processData(42);

31 439

What is the output?

Anonymous voting

31 439

CHALLENGE

class CustomError extends Error {
  constructor(message, code) {
    super(message);
    this.name = 'CustomError';
    this.code = code;
  }
}

try {
  throw new CustomError('Something went wrong', 500);
} catch (error) {
  console.log(error instanceof Error);
  console.log(error instanceof CustomError);
  console.log(error.name);
  console.log(typeof error.code);
}

31 439

What is the output?

Anonymous voting

31 439

CHALLENGE

let cache = new Map();
let obj = { name: 'Emma', age: 28 };

function memoize(fn) {
  return function(...args) {
    const key = JSON.stringify(args);
    if (cache.has(key)) {
      console.log('Cache hit');
      return cache.get(key);
    }
    const result = fn.apply(this, args);
    cache.set(key, result);
    return result;
  };
}

const process = memoize((data) => {
  console.log('Processing:', data.name);
  return data.age * 2;
});

process(obj);
process(obj);
obj.age = 30;
process(obj);
console.log('Cache size:', cache.size);

31 439

⛽️ npm-check-updates 18.2: Update package.json Dependencies to Latest Versions That is, as opposed to the specified versions. Includes a handy -i interactive mode so you can look at potential upgrades and then opt in to them one by one. v18.2 adds a ‘cooldown’ feature to help protect against supply chain attacks by requiring package versions to be published at least the given number of days before considering them for upgrade. Raine Revere

31 439

What is the output?

Anonymous voting

31 439

CHALLENGE

const pattern = /(?<=\d)(?=(?:\d{3})+(?!\d))/g;
const str = '1234567890';
const result = str.replace(pattern, ',');
console.log(result);

const regex = /^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)[a-zA-Z\d]{8,}$/;
const tests = ['Password1', 'password', 'PASSWORD1', 'Pass1'];
tests.forEach(test => {
  console.log(`${test}: ${regex.test(test)}`);
});

const capture = /([a-z]+)(\d+)/g;
const text = 'item123 product456';
const matches = [...text.matchAll(capture)];
console.log(matches[1][1]);

31 439

🥳 IINA is a popular, open-source media player for macOS and it has just added a JavaScript-based plugin system to let users extend its functionality.

31 439

What is the output?

Anonymous voting

31 439

CHALLENGE

const sym1 = Symbol('test');
const sym2 = Symbol('test');
const obj = {
  [sym1]: 'value1',
  [sym2]: 'value2',
  regular: 'value3'
};

const sym3 = Symbol.for('global');
const sym4 = Symbol.for('global');

console.log(sym1 === sym2);
console.log(sym3 === sym4);
console.log(Object.keys(obj).length);
console.log(Object.getOwnPropertySymbols(obj).length);

31 439

⛽️ Massive Supply Chain Attack Hijacks ctrl/tinycolor With 2 Million Downloads and Other 40 NPM Packages A sophisticated and widespread supply chain attack has struck the NPM ecosystem, compromising the popular @ctrl/tinycolor package, which is downloaded over 2 million times per week. Guru Baran

31 439

What is the output?

Anonymous voting

31 439

CHALLENGE

const cache = new Map();

function createHandler(id) {
  const data = { id, value: new Array(1000).fill(id) };
  cache.set(id, data);
  
  return function(action) {
    if (action === 'get') return data;
    if (action === 'clear') cache.delete(id);
  };
}

const handler1 = createHandler('user-1');
const handler2 = createHandler('user-2');

handler1('clear');
console.log(cache.size);
console.log(handler1('get').id);

31 439

🤩 Fetch Streams are Great, But Not for Measuring Upload/Download Progress Fetch upload streams seem well-suited for tracking the progress of uploads, but as Jake notes “just because stuff is taken from the stream doesn’t mean it’s yet been sent over the network”. He also touches on an issue relating to measuring download progress using response streams. Jake Archibald