Skip to main content

Function promisification

Nov 19, 2022CodeCatch
Loading...

More JavaScript Posts

Destructuring Assignment

Nov 19, 2022CodeCatch

0 likes • 0 views

//JavaScript program to swap two variables
//take input from the users
let a = prompt('Enter the first variable: ');
let b = prompt('Enter the second variable: ');
//using destructuring assignment
[a, b] = [b, a];
console.log(`The value of a after swapping: ${a}`);
console.log(`The value of b after swapping: ${b}`);

linked list

Nov 19, 2022CodeCatch

0 likes • 1 view

class LinkedList {
constructor() {
this.nodes = [];
}
get size() {
return this.nodes.length;
}
get head() {
return this.size ? this.nodes[0] : null;
}
get tail() {
return this.size ? this.nodes[this.size - 1] : null;
}
insertAt(index, value) {
const previousNode = this.nodes[index - 1] || null;
const nextNode = this.nodes[index] || null;
const node = { value, next: nextNode };
if (previousNode) previousNode.next = node;
this.nodes.splice(index, 0, node);
}
insertFirst(value) {
this.insertAt(0, value);
}
insertLast(value) {
this.insertAt(this.size, value);
}
getAt(index) {
return this.nodes[index];
}
removeAt(index) {
const previousNode = this.nodes[index - 1];
const nextNode = this.nodes[index + 1] || null;
if (previousNode) previousNode.next = nextNode;
return this.nodes.splice(index, 1);
}
clear() {
this.nodes = [];
}
reverse() {
this.nodes = this.nodes.reduce(
(acc, { value }) => [{ value, next: acc[0] || null }, ...acc],
[]
);
}
*[Symbol.iterator]() {
yield* this.nodes;
}
}
const list = new LinkedList();
list.insertFirst(1);
list.insertFirst(2);
list.insertFirst(3);
list.insertLast(4);
list.insertAt(3, 5);
list.size; // 5
list.head.value; // 3
list.head.next.value; // 2
list.tail.value; // 4
[...list.map(e => e.value)]; // [3, 2, 1, 5, 4]
list.removeAt(1); // 2
list.getAt(1).value; // 1
list.head.next.value; // 1
[...list.map(e => e.value)]; // [3, 1, 5, 4]
list.reverse();
[...list.map(e => e.value)]; // [4, 5, 1, 3]
list.clear();
list.size; // 0

JS Test

Mar 9, 2021LeifMessinger

0 likes • 1 view

alert("bruh")

Redux Setup

Mar 11, 2021C S nre

0 likes • 0 views

import { configureStore } from "@reduxjs/toolkit";
import { combineReducers } from "redux";
import profile from "./profile";
import auth from "./auth";
import alert from "./alert";
const reducer = combineReducers({
profile,
auth,
alert,
});
const store = configureStore({ reducer });
export default store;

typewriter-effect in Vanilla JS and React

Jan 25, 2023C S nre

0 likes • 7 views

// Vanilla JS Solution:
var app = document.getElementById('app');
var typewriter = new Typewriter(app, { loop: true });
typewriter
.typeString("I'm John and I'm a super cool web developer")
.pauseFor(3000)
.deleteChars(13) // "web developer" = 13 characters
.typeString("person to talk with!") // Will display "I'm John and I'm a super cool person to talk with!"
.start();
// React Solution:
import Typewriter from 'typewriter-effect';
<Typewriter
options={{ loop: true }}
onInit={typewriter => {
typewriter
.typeString("I'm John and I'm a super cool web developer")
.pauseFor(3000)
.deleteChars(13) // "web developer" = 13 characters
.typeString("person to talk with!") // Will display "I'm John and I'm a super cool person to talk with!"
.start();
}}
/>

native data structures

Nov 19, 2022CodeCatch

0 likes • 0 views

const nums = [1, 2, 3];
const strs = Array.from('est');
nums.push(6);
nums.push(4, 9);
strs.unshift('t');
nums.length; // 6
nums[nums.length - 1]; // 9
strs[0]; // 't'
strs[2]; // 's'
nums.slice(1, 3); // [2, 3]
nums.map(n => n * 2); // [2, 4, 6, 12, 8, 18]
nums.filter(n => n % 2 === 0); // [2, 6, 4]
nums.reduce((a, n) => a + n, 0); // 25
strs.reverse(); // ['t', 's', 'e', 't']
strs.join(''); // 'test'
const nums = new Set([1, 2, 3]);
nums.add(4);
nums.add(1);
nums.add(5);
nums.add(4);
nums.size; // 5
nums.has(4); // true
nums.delete(4);
nums.has(4); // false
[...nums]; // [1, 2, 3, 5]
nums.clear();
nums.size; // 0
const items = new Map([
[1, { name: 'John' }],
[2, { name: 'Mary' }]
]);
items.set(4, { name: 'Alan' });
items.set(2, { name: 'Jeff' });
items.size; // 3
items.has(4); // true
items.get(2); // { name: 'Jeff' }
items.delete(2);
items.size; // 2
[...items.keys()]; // [1, 4]
[...items.values()]; // [{ name: 'John' }, { name: 'Alan' }]
items.clear();
items.size; // 0