Jason Oboti

Posted on Aug 18, 2022

Create a password generator with Vanilla JS, Html and css

#javascript #beginners #tutorial #html

Note worthy 📝

This article assumes that you already know basic html, Css and Javascript.

Let's Start

First open up your favorite code editor...I use Vs code, you could use any that your familiar with
Create a folder with the project name which we would call

password-generator.

Open the folder and create the index.html file for our markup.
Using the emmet key of shift key + ! you would get something like this

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>

</body>
</html>

In the body tag create the skeleton of the page that looks like this

    <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>

Then we move to the CSS for styling
Create a new file and name it style.css
Now link the CSS file to the html page by attaching <link rel="stylesheet" href="style.css" /> in the <head> tag

we would set Our CSS box and body properties now

* {
    box-sizing: border-box;
}

body {
    background-image: linear-gradient(110deg, #f01313, rgb(97, 167, 18));
    color: #fff;
    display: flex;
    font-family: 'Varela Round', sans-serif;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 10px;
    min-height: 100vh;
    overflow: hidden;
}

I used a linear gradient, you could play around wirh the colors tho.
Set the p, h and input tags to your preferred style

p {
    margin: 5px 0;
}

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

input[type=checkbox] {
    margin-right: 0;
}

Now the rest of the styling

.container {
    background-image: linear-gradient(110deg, rgb(58, 18, 167), #d74242);
    box-shadow: 0px 5px 10px rgba(227, 212, 212, 0.338);
    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);
}

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

.btn {
    border: none;
    color: #fff;
    cursor: pointer;
    font-size: 16px;
    padding: 8px 12px;
    background-color: #4a244a;
}

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

.setting {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin: 15px 0;
}

@media screen and (max-width: 400px) {
    .result-container {
        font-size: 14px;
    }
}

We are done with the styling... initiate more design ides were possible

Now we move to the Javascript

Create a file named app.js and link it to the html at the bottom of the page in between the closing </body> and </html> tags, like:

<script src="main.js"></script>

In the app.js file, we first manipulate the DOM by getting the elements by the Id names in the html:

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 clipboard = document.getElementById('clipboard');

Now we have to make the styled page to be a working active page

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

clipboard.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');
});

generate.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]);

    // Doesn't have a selected type
    if(typesCount === 0) {
        return '';
    }

    // create a loop
    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)];
}

First we create Event listeners for the clipboard and buttons... wait I forgot to attach the font awesome code for the clipboard.
Here it is <script
src="https://kit.fontawesome.com/db3fa2690b.js"
crossorigin="anonymous"

to be attached before or after the other <script> tag in the html
Now the clipboard

clipboard.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');
});

Then we add Event listeners to the generate button, here we created a const variable with the value that

Checks the length of the password
Put a check mark on the lowercaseEl, uppercaseEl, numbersEl, symbolsEl elements with a value of checked

generate.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);
});

Now we write a function that generates random password

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]);

    // Doesn't have a selected type
    if(typesCount === 0) {
        return '';
    }

    // create a loop
    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;
}

Now create random numbers from the character code encoding

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)];
}

We have to get back to the top now and create a new variable object that stores the random function

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

Hurray 🥳

Now we've successfully built a password generator... this is one of my first projects in my coding journey So I decided to share it here

Check out the source on GitHub: https://github.com/JasonOboti/Password-Generator

If you followed along you should have something like this

DEV Community

Create a password generator with Vanilla JS, Html and css

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