<!DOCTYPE html>
<!--Codingthai.com--> 
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.14.0/css/all.min.css" integrity="sha512-1PKOgIY59xJ8Co8+NE6FZ+LOAZKjy+KY8iq0G4B3CyeY6wYHN3yt9PW0XpSriVlkMXe40PTKnXrLnZ9+fkDaog==" crossorigin="anonymous" />
    <link rel="stylesheet" href="style.css" />
    <title>Password Generator</title>
  </head>
  <body>
    <div class="container">
      <h2>Password Generator</h2>
      <div class="result-container">
        <span id="result"></span>
        <button class="btn" id="clipboard">
          <i class="far fa-clipboard"></i>
        </button>
      </div>
      <div class="settings">
        <div class="setting">
          <label>Password Length</label>
          <input type="number" id="length" min="4" max="20" value="20">
        </div>
        <div class="setting">
          <label>Include uppercase letters</label>
          <input type="checkbox" id="uppercase" checked>
        </div>
        <div class="setting">
          <label>Include lowercase letters</label>
          <input type="checkbox" id="lowercase" checked>
        </div>
        <div class="setting">
          <label>Include numbers</label>
          <input type="checkbox" id="numbers" checked>
        </div>
        <div class="setting">
          <label>Include symbols</label>
          <input type="checkbox" id="symbols" checked>
        </div>
      </div>

      <button class="btn btn-large" id="generate">
        Generate Password
      </button>
    </div>
    <script src="script.js"></script>
  </body>
</html>
@import url('https://fonts.googleapis.com/css?family=Muli&display=swap');

* {
  box-sizing: border-box;
}

body {
  background-color: #3b3b98;
  color: #fff;
  font-family: 'Muli', sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100vh;
  overflow: hidden;
  padding: 10px;
  margin: 0;
}

h2 {
  margin: 10px 0 20px;
  text-align: center;
}

.container {
  background-color: #23235b;
  box-shadow: 0px 2px 10px rgba(255, 255, 255, 0.2);
  padding: 20px;
  width: 350px;
  max-width: 100%;
}

.result-container {
  background-color: rgba(0, 0, 0, 0.4);
  display: flex;
  justify-content: flex-start;
  align-items: center;
  position: relative;
  font-size: 18px;
  letter-spacing: 1px;
  padding: 12px 10px;
  height: 50px;
  width: 100%;
}

.result-container #result {
  word-wrap: break-word;
  max-width: calc(100% - 40px);
  overflow-y: scroll;
  height: 100%;
}

#result::-webkit-scrollbar {
  width: 1rem;
}

.result-container .btn {
  position: absolute;
  top: 5px;
  right: 5px;
  width: 40px;
  height: 40px;
  font-size: 20px;
}

.btn {
  border: none;
  background-color: #3b3b98;
  color: #fff;
  font-size: 16px;
  padding: 8px 12px;
  cursor: pointer;
}

.btn-large {
  display: block;
  width: 100%;
}

.setting {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin: 15px 0;
}
const resultEl = document.getElementById('result')
const lengthEl = document.getElementById('length')
const uppercaseEl = document.getElementById('uppercase')
const lowercaseEl = document.getElementById('lowercase')
const numbersEl = document.getElementById('numbers')
const symbolsEl = document.getElementById('symbols')
const generateEl = document.getElementById('generate')
const clipboardEl = document.getElementById('clipboard')

const randomFunc = {
    lower: getRandomLower,
    upper: getRandomUpper,
    number: getRandomNumber,
    symbol: getRandomSymbol
}

clipboardEl.addEventListener('click', () => {
    const textarea = document.createElement('textarea')
    const password = resultEl.innerText

    if(!password) { return }

    textarea.value = password
    document.body.appendChild(textarea)
    textarea.select()
    document.execCommand('copy')
    textarea.remove()
    alert('Password copied to clipboard!')
})

generateEl.addEventListener('click', () => {
    const length = +lengthEl.value
    const hasLower = lowercaseEl.checked
    const hasUpper = uppercaseEl.checked
    const hasNumber = numbersEl.checked
    const hasSymbol = symbolsEl.checked

    resultEl.innerText = generatePassword(hasLower, hasUpper, hasNumber, hasSymbol, length)
})

function generatePassword(lower, upper, number, symbol, length) {
    let generatedPassword = ''
    const typesCount = lower + upper + number + symbol
    const typesArr = [{lower}, {upper}, {number}, {symbol}].filter(item => Object.values(item)[0])
    
    if(typesCount === 0) {
        return ''
    }

    for(let i = 0; i < length; i += typesCount) {
        typesArr.forEach(type => {
            const funcName = Object.keys(type)[0]
            generatedPassword += randomFunc[funcName]()
        })
    }

    const finalPassword = generatedPassword.slice(0, length)

    return finalPassword
}

function getRandomLower() {
    return String.fromCharCode(Math.floor(Math.random() * 26) + 97)
}

function getRandomUpper() {
    return String.fromCharCode(Math.floor(Math.random() * 26) + 65)
}

function getRandomNumber() {
    return String.fromCharCode(Math.floor(Math.random() * 10) + 48)
}

function getRandomSymbol() {
    const symbols = '!@#$%^&*(){}[]=<>/,.'
    return symbols[Math.floor(Math.random() * symbols.length)]
}
Run Pen

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.