Are you passionate about JavaScript? Do you want to stay updated on the latest news, articles, books, and updates in the world of #javascript? Look no further than our resourceful newsletter - JavaScript! This channel is dedicated to providing you with valuable information about everything related to JavaScript, so you never miss out on any important updates. We also offer fun quizzes to test your knowledge and engage with other members of the community. Join us today and be part of the conversation! Let's chat and learn together at @nairihar. Don't miss out on the opportunity to expand your JavaScript knowledge and network with like-minded individuals. Stay informed, stay connected with JavaScript!
16 Feb, 13:15
16 Feb, 06:31
let weakmap = new WeakMap();
let obj1 = {};
let obj2 = {};
weakmap.set(obj1, 'value1');
weakmap.set(obj2, 'value2');
obj1 = null;
console.log(weakmap.has(obj1));
15 Feb, 13:14
15 Feb, 06:33
const promise = new Promise((resolve, reject) => {
reject('Error occurred');
});
promise
.then(() => {
console.log('Promise resolved!');
})
.catch(error => {
console.log(error);
})
.then(() => {
console.log('Process completed');
}); 14 Feb, 06:32
function outerFunction() {
let x = 10;
function innerFunction() {
x += 5;
console.log(x);
}
return innerFunction;
}
const closureFunc = outerFunction();
closureFunc();
closureFunc(); 13 Feb, 06:33
const symbol1 = Symbol('symbol');
const symbol2 = Symbol('symbol');
const obj = {};
obj[symbol1] = 'value1';
obj[symbol2] = 'value2';
console.log(obj[symbol1]); 12 Feb, 13:54
12 Feb, 06:35
function* numberGenerator() {
yield 1;
yield 2;
yield 3;
}
const gen = numberGenerator();
console.log(gen.next().value);
console.log(gen.next().value);
console.log(gen.next().value);
console.log(gen.next().value); 11 Feb, 06:34
'use strict';
function strictModeExample() {
undeclaredVariable = 10;
try {
console.log(undeclaredVariable);
} catch (e) {
console.log('Error:', e.message);
}
}
strictModeExample();
10 Feb, 13:06
09 Feb, 13:05
09 Feb, 06:35
const a = '5';
const b = 5;
const c = 10;
const result1 = a == b;
const result2 = a === b;
const result3 = b < c;
const result4 = b >= c;
console.log(result1, result2, result3, result4);
05 Feb, 06:34
const numbers = [1, 2, 3, 4, 5];
const result = numbers
.filter(n => n % 2 === 0)
.map(n => n * 2)
.reduce((acc, n) => acc + n, 0);
console.log(result);
04 Feb, 13:32
04 Feb, 06:34
const wm = new WeakMap();
const obj1 = {};
const obj2 = {};
wm.set(obj1, 'object 1');
wm.set(obj2, 'object 2');
wm.delete(obj1);
console.log(wm.has(obj1));
03 Feb, 13:31
03 Feb, 06:34
let symbol1 = Symbol('description');
let symbol2 = Symbol('description');
const obj = {
[symbol1]: 'value1',
[symbol2]: 'value2'
};
console.log(obj[symbol1]);
console.log(symbol1 === symbol2);
02 Feb, 12:30
02 Feb, 06:35
function tricky() {
let a = 1;
let b = 2;
const result = (function(a) {
a = 3;
return a + b;
})(a);
return result;
}
console.log(tricky()); 01 Feb, 06:34
function mysteriousFunction(a) {
let result = 0;
for (let i = 1; i <= a; i++) {
if (i % 3 === 0 && i % 5 === 0) {
result += i * 2;
} else if (i % 3 === 0) {
result += i;
} else if (i % 5 === 0) {
result -= i;
}
}
return result;
}
console.log(mysteriousFunction(15)); 31 Jan, 18:40
31 Jan, 06:34
function mystery(x) {
return (function(y) {
return x + y;
})(x * 2);
}
const result1 = mystery(2);
const result2 = mystery(5);
const result3 = mystery(-1);
console.log(result1, result2, result3); 30 Jan, 06:33
function trickyCount(n) {
if (n <= 1) return n;
return trickyCount(n - 1) + trickyCount(n - 2);
}
function wrapCount(n) {
return trickyCount(n) - trickyCount(n - 4);
}
console.log(wrapCount(6)); 29 Jan, 13:39
29 Jan, 06:32
var arr = Array.from({ length: 5 }, (v, i) => i * 2);
console.log(arr); 28 Jan, 13:06
28 Jan, 06:31
const person = {
name: "Alice",
age: 30,
city: "New York"
};
const keys = Object.keys(person);
const values = Object.values(person);
const result = keys.map((key, index) => `${key}: ${values[index]}`);
console.log(result); 27 Jan, 13:04
27 Jan, 06:34
let arr = [1, 2, 3, 4, 5];
arr.length = 3;
console.log(arr.length);
console.log(arr);
26 Jan, 13:03
26 Jan, 06:34
let arr = [1, 2, 3, 4, 5];
arr.length = 3;
arr.push(6, 7);
console.log(arr.length);
25 Jan, 13:47
25 Jan, 06:32
const students = [
{ name: 'Alice', age: 20 },
{ name: 'Bob', age: 22 },
{ name: 'Charlie', age: 23 }
];
const studentToFind = { name: 'Bob', age: 22 };
const isIncluded = students.includes(studentToFind);
console.log(isIncluded);
24 Jan, 13:56
24 Jan, 06:34
const numbers = [10, 23, 45, 60, 78];
const isDivisibleByFive = numbers.some(num => num % 5 === 0);
if (isDivisibleByFive) {
console.log('Some numbers are divisible by 5');
} else {
console.log('No numbers are divisible by 5');
}
23 Jan, 13:52
23 Jan, 06:32
const numbers = [2, 4, 6, 8, 10];
const allEven = numbers.every(function(num) {
return num % 2 === 0;
});
console.log(allEven);
22 Jan, 13:51
22 Jan, 06:31
var obj = {
a: 10,
b: 20
};
with (obj) {
var result = a + b;
}
console.log(result); 21 Jan, 06:33
function getNextWeekday(dateString) {
const date = new Date(dateString);
const day = date.getDay();
const diff = (day === 0 ? 1 : 8) - day;
date.setDate(date.getDate() + diff);
return date.toDateString();
}
console.log(getNextWeekday('2023-10-20')); 20 Jan, 13:45
20 Jan, 06:32
function* numberGenerator() {
for (let i = 0; i < 3; i++) {
yield i * 2;
}
}
const numbers = [...numberGenerator()];
console.log(numbers); 19 Jan, 13:43
19 Jan, 06:33
function trickyArgs(a, b, c) {
arguments[0] = 10;
arguments[1] = 20;
arguments[2] = 30;
console.log(a + b + c);
}
trickyArgs(1, 2, 3); 18 Jan, 13:42
18 Jan, 06:33
class Vehicle {
static type() {
return "Generic Vehicle";
}
}
class Car extends Vehicle {
static type() {
return "Car";
}
}
console.log(Car.type()); 17 Jan, 13:26
17 Jan, 06:35
function multiply(a, b = a * 2) {
return a * b;
}
console.log(multiply(3)); 16 Jan, 13:05
16 Jan, 06:33
const a = '10';
const b = 20;
const c = '30.5';
const result = Number(a) + b + Number.parseFloat(c);
console.log(result);
15 Jan, 13:02
15 Jan, 06:31
let str = "Hello, World!";
let result = str.substring(7, 12);
console.log(result);
14 Jan, 13:02
14 Jan, 06:34
function displayArguments() {
console.log(arguments.length);
console.log(arguments[0]);
console.log(arguments[2]);
}
displayArguments('Hello', 'World', 'JavaScript', 'Quiz'); 13 Jan, 13:05
13 Jan, 06:35
function trickyFunction() {
let a = 5;
let b = '5';
let c = 5;
if (a == b && b === c) {
console.log('Condition 1');
} else if (a === c || b == c) {
console.log('Condition 2');
} else {
console.log('Condition 3');
}
}
trickyFunction(); 12 Jan, 09:02
12 Jan, 06:31
var obj = { a: 10, b: 20 };
with (obj) {
var result = a + b;
}
console.log(result); 11 Jan, 16:51
11 Jan, 06:32
const myObject = {
a: 1,
b: 2,
c: 3,
[Symbol.iterator]: function* () {
for (let key of Object.keys(this)) {
yield this[key];
}
}
};
const iter = myObject[Symbol.iterator]();
console.log(iter.next().value);
console.log(iter.next().value);
console.log(iter.next().value); 10 Jan, 06:32
function* customGenerator() {
yield 'Hello';
yield 'World';
return 'Done';
}
const gen = customGenerator();
console.log(gen.next().value);
console.log(gen.next().value);
console.log(gen.next().value); 09 Jan, 06:32
const mySet = new Set();
mySet.add(10);
mySet.add(20);
mySet.add(10);
mySet.add(30);
console.log(mySet.size);
08 Jan, 06:32
const WM = new WeakMap();
let obj = {};
let anotherObj = {};
WM.set(obj, 'object data');
WM.set(anotherObj, 'another object data');
obj = null;
// Let's check what's logged
console.log(WM.has(obj));
console.log(WM.has(anotherObj));
07 Jan, 06:33
async function fetchData() {
let data = 'initial';
const promise = new Promise((resolve) => {
setTimeout(() => {
resolve('fetched');
}, 1000);
});
promise.then((result) => {
data = result;
});
return data;
}
fetchData().then(console.log); 06 Jan, 06:32
function trickyFunction() {
var obj = { a: 1 };
var anotherObj = obj;
obj.a = 2;
obj = { a: 3 };
anotherObj.a = 4;
return obj.a + anotherObj.a;
}
console.log(trickyFunction()); 05 Jan, 13:25
05 Jan, 06:32
function trickyFunction() {
var x = 10;
if (x > 5) {
let y = x * 2;
x = y;
}
return x;
}
console.log(trickyFunction()); 04 Jan, 12:26
04 Jan, 06:35
function trickyFunction() {
var a = 10;
var b = a;
b = 15;
const obj1 = { x: 1 };
const obj2 = obj1;
obj2.x = 5;
console.log(a + ' ' + b + ' ' + obj1.x);
}
trickyFunction(); 03 Jan, 06:30
const obj = {
valueOf() {
return 42;
}
};
const result = obj + 8;
console.log(result);
02 Jan, 06:31
function combine(...arrays) {
return arrays.reduce((acc, arr) => [...acc, ...arr], []);
}
const result = combine([1, 2], [3, 4], [5, 6]);
console.log(result);
28 Dec, 08:31
27 Dec, 05:51
25 Dec, 12:48
16 Dec, 05:01
15 Dec, 13:31
15 Dec, 06:30
let a = 5; // binary: 101
let b = 3; // binary: 011
let result = a ^ b;
console.log(result);
14 Dec, 13:30
09 Dec, 13:45
09 Dec, 06:30
class MyClass {
constructor() {
this.a = 10;
}
}
MyClass.prototype.b = 20;
const obj = new MyClass();
delete obj.b;
console.log(obj.b);
08 Dec, 13:43
08 Dec, 06:30
const map = new Map();
map.set("key", undefined);
console.log(map.has("key"), map.get("key"));
07 Dec, 06:30
const obj = {
0: "zero",
1: "one",
length: 2
};
console.log(Array.from(obj)); 06 Dec, 13:38
06 Dec, 06:31
function foo() {}
foo.prototype.bar = 42;
const obj = new foo();
foo.prototype = { bar: 100 };
console.log(obj.bar);
05 Dec, 13:36
05 Dec, 06:30
(async function() {
return await 10;
})().then(console.log);
04 Dec, 13:35
04 Dec, 06:30
const nums = [1, 2, 3];
const res = nums.reduce((acc, val) => acc + val, "");
console.log(typeof res);
03 Dec, 13:02
02 Dec, 15:32
02 Dec, 07:01
const obj = {
a: 1,
b: function() {
return this.a;
}
};
const b = obj.b;
console.log(b());
01 Dec, 14:30
30 Nov, 13:35
30 Nov, 06:30
const obj = { a: 1 };
Object.seal(obj);
obj.b = 2;
console.log(obj.b);
28 Nov, 06:30
const obj = {};
Object.defineProperty(obj, "prop", {
value: 42,
writable: false
});
obj.prop = 100;
console.log(obj.prop);
27 Nov, 13:24
27 Nov, 06:30
const x = (() => {
try {
return 10;
} finally {
return 20;
}
})();
console.log(x);
26 Nov, 13:23
26 Nov, 06:30
const arr = [1, 2, 3];
arr[-1] = 10;
console.log(arr.length, arr[-1]);
24 Nov, 12:30
23 Nov, 07:48
22 Nov, 07:49
22 Nov, 06:30
const obj = {
valueOf: () => 42,
toString: () => "Hello"
};
console.log(`${obj}`, obj + 10); 20 Nov, 07:47
18 Nov, 05:02
17 Nov, 12:02
17 Nov, 06:30
console.log([โฆ({ [Symbol.iterator]: function*(){ yield *[1, yield *[2,3] ] } })])
16 Nov, 11:58
16 Nov, 06:31
Number.prototype[Symbol.iterator] = function*() { yield *['a','b','c'] };
console.log([...1]);
15 Nov, 04:56
12 Nov, 13:49
12 Nov, 06:30
const arr = [1, 2, 3];
arr[10] = 11;
console.log(arr.length);
11 Nov, 06:30
const name = "Alice";
const obj = {
name: "Bob",
getName() {
return this.name;
}
};
console.log(obj.getName.call({ name: "Charlie" }));
10 Nov, 06:30
const sym1 = Symbol("id");
const sym2 = Symbol("id");
console.log(sym1 === sym2);
09 Nov, 13:05
09 Nov, 06:30
let name = "Alice";
(function() {
let name = "Bob";
console.log(name);
})();
console.log(name);
08 Nov, 13:03
??= nullish coalescing assignment operator snuck into JavaScript a few years ago via ECMAScript 2021 and has been broadly supported almost everywhere for ages. Trevor shows off how it can tighten up your assignments here.07 Nov, 06:30
const arr = [1, 2, 3];
const copy = [...arr];
copy.push(4);
console.log(arr);
console.log(copy);
06 Nov, 13:53
06 Nov, 06:30
async function test() {
return (await Promise.resolve(0)) || 10;
}
test().then(console.log);
05 Nov, 13:24
05 Nov, 06:30
const obj = { value: 10 };
const result = (obj.value += 5) && obj.value;
console.log(result);
04 Nov, 13:44
04 Nov, 06:30
const factorial = (function () {
const cache = {};
return function inner(n) {
if (n in cache) return cache[n];
return (cache[n] = n <= 1 ? 1 : n * inner(n - 1));
};
})();
console.log(factorial(5));
console.log(factorial(5));
03 Nov, 13:22
03 Nov, 06:30
function Person(name) {
this.name = name;
this.sayName = () => console.log(this.name);
}
const person1 = new Person('David');
const person2 = { name: 'Not David', sayName: person1.sayName };
person2.sayName();
02 Nov, 06:30
const a = false || 0 || "" || null || "JavaScript";
console.log(a);
31 Oct, 13:21
31 Oct, 06:30
function memoize(fn) {
const cache = {};
return (arg) => cache[arg] ?? (cache[arg] = fn(arg));
}
const square = memoize((n) => n * n);
console.log(square(5));
console.log(square(5));
console.log(square(6));
30 Oct, 13:43
30 Oct, 06:30
console.log('A');
setTimeout(() => console.log('B'), 0);
Promise.resolve()
.then(() => {
console.log('C');
return Promise.resolve();
})
.then(() => console.log('D'));
console.log('E');
29 Oct, 13:07
29 Oct, 06:30
console.log(typeof null);
console.log(typeof function () {});
28 Oct, 13:34
28 Oct, 06:30
const obj = {
value: 10,
getValue: function () {
return () => this.value;
}
};
const value = 20;
const getValue = obj.getValue();
console.log(getValue());
27 Oct, 06:30
function Animal(name) {
this.name = name;
}
Animal.prototype.sound = 'Generic sound';
const dog = new Animal('Dog');
Animal.prototype.sound = 'Bark';
console.log(dog.sound);
26 Oct, 13:35
26 Oct, 06:30
async function test() {
console.log(1);
await new Promise(resolve => setTimeout(resolve, 1000));
console.log(2);
return 3;
}
console.log(4);
test().then(console.log);
console.log(5);
24 Oct, 15:45
require() by default, drops 32-bit Windows support, and node --run goes stable.24 Oct, 06:30
function Person(name) {
this.name = name;
}
Person.prototype.greet = function () {
console.log(`Hello, ${this.name}`);
};
const person = new Person('Alice');
person.greet();
console.log(person.hasOwnProperty('greet'));
23 Oct, 13:51
23 Oct, 06:30
for (var i = 0; i < 3; i++) {
setTimeout(() => console.log(i), 100);
}
22 Oct, 13:42
npx is-my-node-vulnerable
22 Oct, 06:30
const sym = Symbol('unique');
const obj = {
[sym]: 'Secret',
public: 'Visible'
};
console.log(Object.keys(obj));
console.log(obj[Symbol('unique')]);
21 Oct, 06:30
Promise.resolve(1)
.then(value => {
console.log(value);
throw new Error('Something went wrong');
})
.then(() => {
console.log('This will not run');
})
.catch(error => {
console.log('Caught:', error.message);
return 42;
})
.then(value => {
console.log('Recovered with:', value);
});
19 Oct, 06:02
18 Oct, 13:17
18 Oct, 06:30
const map = new Map();
const key1 = {};
const key2 = key1;
map.set(key1, "Value for key1");
map.set(key2, "Value for key2");
console.log(map.get({}));
console.log(map.get(key1));
17 Oct, 13:49
17 Oct, 06:30
const obj = {};
Object.defineProperty(obj, 'name', {
value: 'Alice',
writable: false,
configurable: false
});
try {
obj.name = 'Bob';
delete obj.name;
console.log(obj.name);
} catch (e) {
console.log('Error:', e.message);
}
16 Oct, 06:30
function processData({ a = 10, b = 20 } = { a: 30 }) {
console.log(a, b);
}
processData({ a: 5 });
processData();
15 Oct, 06:30
function* numberGenerator() {
let i = 0;
while (i < 3) {
yield i++;
}
}
const gen = numberGenerator();
console.log(gen.next().value);
console.log(gen.return(10).value);
console.log(gen.next().value);
14 Oct, 06:31
const obj = Object.freeze({
name: "Alice",
info: {
age: 25
}
});
try {
obj.name = "Bob";
obj.info.age = 30;
} catch (e) {
console.log("Error:", e.message);
}
console.log(obj.name, obj.info.age);
13 Oct, 13:22
13 Oct, 06:30
async function first() {
console.log('First Start');
await second();
console.log('First End');
}
async function second() {
console.log('Second Start');
}
console.log('Script Start');
first();
setTimeout(() => console.log('Timeout'), 0);
console.log('Script End');
12 Oct, 13:20
