React - Lifting State · JavaScript

React - Lifting State

• Jan 25, 2023 •C S

More JavaScript Posts

MongoDB Connection

• Oct 15, 2022 •CodeCatch

3 likes • 4 views

const MongoClient = require('mongodb').MongoClient;
const assert = require('assert');

// Connection URL
const url = 'mongodb://localhost:27017';

// Database Name
const dbName = 'myproject';

// Use connect method to connect to the server
MongoClient.connect(url, function(err, client) {
  assert.equal(null, err);
  console.log("Connected successfully to server");

  const db = client.db(dbName);

  client.close();
});

Longest Palindromic Substring

• Nov 19, 2022 •CodeCatch

0 likes • 2 views

JavaScript

const longestPalindrome = (s) => {
    if(s.length === 1) return s
    
    const odd = longestOddPalindrome(s)
    const even = longestEvenPalindrome(s)
    
    
    if(odd.length >= even.length) return odd
    if(even.length > odd.length) return even
};

const longestOddPalindrome = (s) => {    
    let longest = 0
    let longestSubStr = ""
    
    for(let i = 1; i < s.length; i++) {
        
        let currentLongest = 1
        let currentLongestSubStr = ""
        let left = i - 1
        let right = i + 1
        
        while(left >= 0 && right < s.length) {
            const leftLetter = s[left]
            const rightLetter = s[right]

            left--
            right++

            if(leftLetter === rightLetter) {
                currentLongest += 2
                currentLongestSubStr = s.slice(left+1, right)
            } else break
        }
        
                        
        if(currentLongest > longest) {
            if(currentLongestSubStr) longestSubStr = currentLongestSubStr 
            else longestSubStr = s[i]
            longest = currentLongest
        }
    }
    
    return longestSubStr
}

const longestEvenPalindrome = (s) => {    
    let longest = 0
    let longestSubStr = ""
    
    for(let i = 0; i < s.length - 1; i++) {
        if(s[i] !== s[i+1]) continue;
        
        let currentLongest = 2
        let currentLongestSubStr = ""
        let left = i - 1
        let right = i + 2
        
        while(left >= 0 && right < s.length) {
            const leftLetter = s[left]
            const rightLetter = s[right]

            left--
            right++
            
            if(leftLetter === rightLetter) {
                currentLongest += 2
                currentLongestSubStr = s.slice(left+1, right)
            } else break
        }
                
                
        if(currentLongest > longest) {
            if(currentLongestSubStr) longestSubStr = currentLongestSubStr
            else longestSubStr = s[i] + s[i+1]
    
            longest = currentLongest
        }
    }
    
    return longestSubStr
}
console.log(longestPalindrome("babad"))

Heroku Production Build

• Mar 11, 2021 •C S

1 like • 1 view

JavaScript

if (process.env.NODE_ENV === "production") {
	app.use(express.static("client/build"));

	app.get("*", (req, res) => {
	res.sendFile(path.resolve(__dirname, "client", "build", "index.html"));
	});
}

Get union of arrays

• Nov 19, 2022 •CodeCatch

0 likes • 0 views

JavaScript

const union = (...arr) => [...new Set(arr.flat())];

// Example
union([1, 2], [2, 3], [3]);     // [1, 2, 3]

geometric progression

• Nov 19, 2022 •CodeCatch

0 likes • 0 views

JavaScript

const geometricProgression = (end, start = 1, step = 2) =>
  Array.from({
    length: Math.floor(Math.log(end / start) / Math.log(step)) + 1,
  }).map((_, i) => start * step ** i);
  
geometricProgression(256); // [1, 2, 4, 8, 16, 32, 64, 128, 256]
geometricProgression(256, 3); // [3, 6, 12, 24, 48, 96, 192]
geometricProgression(256, 1, 4); // [1, 4, 16, 64, 256]

next cpu

• Nov 18, 2022 •AustinLeath

0 likes • 2 views

JavaScript

import Head from 'next/head'
import Image from 'next/image'
import styles from '../styles/Home.module.css'


const { exec } = require("child_process");

exec("sensors|grep "high"|grep "Core"|cut -d "+" -f2|cut -d "." -f1|sort -nr|sed -n 1p", (error, stdout, stderr) => {
    if (error) {
        console.log(`error: ${error.message}`);
        return;
    }
    if (stderr) {
        console.log(`stderr: ${stderr}`);
        return;
    }
    console.log(`stdout: ${stdout}`);
});

export default function Home() {
  return (
    <div className={styles.container}>
      <Head>
        <title>Create Next App</title>
        <meta name="description" content="Generated by create next app" />
        <link rel="icon" href="/favicon.ico" />
      </Head>

      <main className={styles.main}>
        <h1 className={styles.title}>
          Welcome to <a href="https://nextjs.org">Next.js!</a>
        </h1>

        <p className={styles.description}>
          Get started by editing{' '}
          <code className={styles.code}>pages/index.js</code>
        </p>

        <div className={styles.grid}>
          <a href="https://nextjs.org/docs" className={styles.card}>
            <h2>Documentation &rarr;</h2>
            <p>Find in-depth information about Next.js features and API.</p>
          </a>

          <a href="https://nextjs.org/learn" className={styles.card}>
            <h2>Learn &rarr;</h2>
            <p>Learn about Next.js in an interactive course with quizzes!</p>
          </a>

          <a
            href="https://github.com/vercel/next.js/tree/canary/examples"
            className={styles.card}
          >
            <h2>Examples &rarr;</h2>
            <p>Discover and deploy boilerplate example Next.js projects.</p>
          </a>

          <a
            href="https://vercel.com/new?utm_source=create-next-app&utm_medium=default-template&utm_campaign=create-next-app"
            className={styles.card}
          >
            <h2>Deploy &rarr;</h2>
            <p>
              Instantly deploy your Next.js site to a public URL with Vercel.
            </p>
          </a>
        </div>
      </main>

      <footer className={styles.footer}>
        <a
          href="https://vercel.com?utm_source=create-next-app&utm_medium=default-template&utm_campaign=create-next-app"
          target="_blank"
          rel="noopener noreferrer"
        >
          Powered by{' '}
          <span className={styles.logo}>
            <Image src="/vercel.svg" alt="Vercel Logo" width={72} height={16} />
          </span>
        </a>
      </footer>
    </div>
  )
}