CHALLENGE
console.log('1');
Promise.resolve().then(() => {
console.log('2');
Promise.resolve().then(() => console.log('3'));
});
Promise.resolve().then(() => {
console.log('4');
});
setTimeout(() => console.log('5'), 0);
console.log('6');❤7👍4
“We’ve been busy,” says Cloudflare which recently announced it’s bringing Node.js HTTP server support to its Workers function platform. This post goes deep into the technicalities, covering what areas of the standard library is supported, how the file system works (Workers doesn’t have a typical file system), how input/output streams work, and more. And you can use all of this now.
James M Snell (Cloudflare)
Please open Telegram to view this post
VIEW IN TELEGRAM
❤8🔥3👍1
CHALLENGE
function processData() {
try {
console.log('processing');
return 'success';
} catch (error) {
console.log('error caught');
return 'failed';
} finally {
console.log('cleanup');
}
}
const result = processData();
console.log('result:', result);🔥2
What is the output?
Anonymous Quiz
13%
error caught cleanup result: failed
50%
processing cleanup result: success
19%
processing cleanup result: undefined
18%
processing result: success cleanup
❤4👍2
Please open Telegram to view this post
VIEW IN TELEGRAM
🤣11❤5👍1
CHALLENGE
class EventEmitter {
constructor() { this.events = {}; }
on(event, fn) { (this.events[event] ||= []).push(fn); }
emit(event, data) { this.events[event]?.forEach(fn => fn(data)); }
}
class Logger {
log(msg) { console.log(`LOG: ${msg}`); }
}
class Counter {
constructor() { this.count = 0; }
increment() { this.count++; console.log(this.count); }
}
function withLogging(target) {
const logger = new Logger();
return new Proxy(target, {
get(obj, prop) {
if (typeof obj[prop] === 'function') {
return function(...args) {
logger.log(`calling ${prop}`);
return obj[prop].apply(obj, args);
};
}
return obj[prop];
}
});
}
const emitter = withLogging(new EventEmitter());
const counter = new Counter();
emitter.on('tick', () => counter.increment());
emitter.emit('tick');
emitter.emit('tick');🤔6
CHALLENGE
class Animal {
constructor(name) {
this.name = name;
}
speak() {
return `${this.name} makes a sound`;
}
}
class Dog extends Animal {
speak() {
return super.speak() + ' and barks';
}
}
const pet = new Dog('Rex');
console.log(pet.speak());
console.log(pet instanceof Animal);
console.log(pet.constructor.name);❤5👍1
What is the output?
Anonymous Quiz
44%
Rex makes a sound and barks true Dog
21%
Rex barks false Dog
26%
Rex makes a sound and barks true Animal
10%
Rex makes a sound true Dog
👍10🤔1
Each year, Devographics runs an epic survey of as many JavaScript community members as it can and turns the results into an interesting report on the state of the ecosystem – here’s the results from 2024. If you have the time, fill it in, especially as they format it in a way where you can actually learn about stuff as you go.
Devographics
Please open Telegram to view this post
VIEW IN TELEGRAM
❤4🤔2🔥1
CHALLENGE
class DataProcessor {
constructor(value) {
this.value = value;
}
transform(fn) {
return new DataProcessor(fn(this.value));
}
getValue() {
return this.value;
}
}
const multiply = x => x * 2;
const add = x => x + 10;
const square = x => x * x;
const result = new DataProcessor(5)
.transform(multiply)
.transform(add)
.transform(square)
.getValue();
console.log(result);❤2
❤8👍3🔥1
CHALLENGE
const Flyable = {
fly() { return 'flying'; }
};
const Swimmable = {
swim() { return 'swimming'; }
};
function mixin(Base, ...mixins) {
mixins.forEach(mixin => Object.assign(Base.prototype, mixin));
return Base;
}
class Bird {}
class Fish {}
const FlyingFish = mixin(class extends Fish {}, Flyable, Swimmable);
const instance = new FlyingFish();
console.log(instance.swim());
console.log(instance.fly());
console.log(instance instanceof Fish);What is the output?
Anonymous Quiz
19%
flying, swimming, false
47%
swimming, flying, true
23%
undefined, undefined, true
10%
swimming, flying, false
❤2🤔1
CHALLENGE
function createCounter() {
let count = 0;
return function(increment = 1) {
count += increment;
return count;
};
}
const counter1 = createCounter();
const counter2 = createCounter();
console.log(counter1());
console.log(counter1(5));
console.log(counter2(3));
console.log(counter1());
console.log(counter2());❤11🤔5
CHALLENGE
const arr = [1, 2, 3, 4, 5];
const obj = { a: 1, b: 2, c: 3 };
const result1 = Object.keys(obj).length;
const result2 = arr.length;
delete obj.b;
obj.d = 4;
const result3 = Object.keys(obj).length;
const result4 = arr.push(6);
arr.length = 3;
const result5 = arr.length;
const result6 = Object.keys(obj).join('');
console.log(result1, result2, result3, result4, result5, result6);
🤔2
What is the output?
Anonymous Quiz
18%
2 5 3 6 3 acd
30%
3 5 2 6 3 adc
17%
3 5 3 7 3 acd
35%
3 5 3 6 3 acd
❤6👍1🔥1
The maintainers of the Deno runtime reflect on the recent npm ecosystem security issues and show off how Deno’s non-permissive explicit ‘secure by default’ model can help.
Andy Jiang
Please open Telegram to view this post
VIEW IN TELEGRAM
❤5🔥3👍2🤩2