index.js

const PwEl = document.getElementById("pw");
const copyEl = document.getElementById("copy");
const lenEl = document.getElementById("len");
const upperEl = document.getElementById("upper");
const lowerEl = document.getElementById("lower");
const symbolEl = document.getElementById("symbol");
const generateEl = document.getElementById("generate");
const numberEl = document.getElementById("number");

const upperLetters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const lowerLetters = "abcdefghijklmnopqrstuvwxyz";
const numbers = "0123456789";
const symbols = "!@#$%^&*()~/\-+-";

function getLowercase() {
    return lowerLetters[Math.floor(Math.random() *
        lowerLetters.length)];
}
function getUppercase() {
    return upperLetters[Math.floor(Math.random() *
        upperLetters.length)];
}
function getNumber() {
    return numbers[Math.floor(Math.random() *
        numbers.length)];
}
function getSymbol() {
    return symbols[Math.floor(Math.random() *
        symbols.length)];
}
function generateX() {
    const xs = [];
    if (upperEl.checked) {
        xs.push(getUppercase());
    }
    if (lowerEl.checked) {
        xs.push(getLowercase());
    }
    if (numberEl.checked) {
        xs.push(getNumber());
    }
    if (symbolEl.checked) {
        xs.push(getSymbol());
    }
    if (xs.length === 0) return "";

    return xs[Math.floor(Math.random() * xs.length)];
}
function generatePassword() {
    const len = lenEl.value;
    var password = [];
    for (let i = 0; i < len; i++) {
        const x = generateX();
        password = password + x;
    }
    PwEl.innerHTML = password;
}

function copytoclipboard(value) {
    navigator.clipboard.writeText(value);
}

generateEl.addEventListener("click", generatePassword);
copyEl.addEventListener("click", () => {
    const textarea = document.createElement("textarea");
    const password = PwEl.innerText;
    if (!password) {
        return;
    }
    copytoclipboard(password);
    alert("Password is Copied to Clipboard");


})