Javascript class how to make it, with a constructor? - forms

Question

Also what are these:
`from selenium import webdriver`
\`def hladaj(vyraz):
driver = webdriver.Chrome()
driver.get('https://www.bing.com/')
search_bar = driver.find_element_by_name('q')
search_bar.send_keys(vyraz)
search_bar.submit()
def otvor(n):
result_links = driver.find_elements_by_css_selector('.b_algo a')
result_links\[n-1\].click()
class Laptop {
constructor(vyrobca, model, rocnik) {
this.vyrobca = vyrobca;
this.model = model;
this.rocnik = rocnik;
}
vypis() {
return `${this.vyrobca},${this.model},${this.rocnik}`;
}
}\`
`<script> // Ziskanie tlacidla var button = document.getElementById("remove"); // Pridanie event listenera na stlacenie tlacidla button.addEventListener("click", function() { // Ziskanie vsetkych elementov s triedou "col" var elements = document.getElementsByClassName("col"); // Prechod cez vsetky elementy for (var i = 0; i < elements.length; i++) { // Zistenie textu v elemente var text = elements[i].textContent; // Ak element obsahuje retazec "Row" if (text.includes("Row")) { // Zmazanie elementu elements[i].parentNode.removeChild(elements[i]); } } }); </script>`
`function o2a(obj){ let final= []; final = Object.keys(objs).map(key=> { let arr = []; arr.push(key); arr.push(obj[key]); return arr; }) return final; }`
`function a2o(arr){ let obj = {} arr.forEach(item=> { obj[item[0]] = item[1]; }); return obj; `
\`import React, { useState } from "react";
function Inp() {
const \[value, setValue\] = useState("");
return (
\<input
value={value}
onChange={(e) =\> setValue(e.target.value)}
placeholder="Input value"
/\>
);
}
function But() {
const \[clicked, setClicked\] = useState(false);
return (
\<button onClick={() =\> setClicked(true)}\>Submit\</button\>
);
}
function Out({ value }) {
return \<div\>{value}\</div\>;
}
function App() {
const \[inputValue, setInputValue\] = useState("");
const handleClick = () =\> {
setInputValue(inputValue);
};
return (
\<div\>
\<Inp /\>
\<But onClick={handleClick} /\>
\<Out value={inputValue} /\>
\</div\>
);
}
export default App;\`
Jazyk javascript bezi defaultne na jednom jadre. Na rozhodnutie toho kedy spusti ktoru funkciu, pouziva event Loop.
Multi-threaded funkcionalitu vieme dosiahnut ponocou builtin API ktore sa nazyva Webliorker. Tento API umoznuje beh paralelnych procesov.
A este tab a browser maju vlastne javascript thready a tak aj prehliadaci je multi thread
const WebSocket = require('ws');
const wss = new WebSocket.Server({ port: 8084 });
let counter = 0;
setInterval(() => {
counter += 2;
}, 2000);
wss.on('connection', (ws) => {
console.log('Connected');
setInterval(() => {
ws.send(counter.toString());
}, 2000);
});
const WebSocket = require('ws');
const ws = new WebSocket('ws://localhost:8084');
ws.on('message', (message) => {
const counter = parseInt(message);
const span = document.createElement('span');
span.textContent = `Aktualny stav pocitadla: ${counter}`;
document.body.appendChild(span);
});
1.prehliada precita kod ako text
2. parsuje to na AST (Abstract Syntax Tree)
3.optimalizuje to
4. vnutorne si ho za behu to kompiluje do bytecode a za behu kontroluje. Pocas kontroly sa engine pozera ze ktore funkcie su ako casto volane, alebo vypoctovo narocne a podla toho ich optimalizuje
const http = require('http');
const fs = require('fs');
const server = http.createServer((req, res)=>{
if (req.method !== 'GET') {
res.end({"error": "error"}")
}else{
if (req.url === '/indexFile'){
fs.readFile('./index.html', function (err, html) {
if (err) {
throw err;
res.writeHeader (200, "Content-Type": "text/html"});
res.write(html);
}
res.end();
if(req.url === '/response'){
const data = fetch('http://esh.op/order').then(res => res.data);
res.writeHead (200, {'Content-Type': 'application/json'});
res.end(JSON.stringify(data));
}
}
});
server.listen(8080)
function conv(str){
str = str.replaceAll(',',"");
str = str.replaceAll(';', "");
str = str.replaceAll('.',"");
return str.split('').sort((a,b) => b.localeCompare(a))
}