React Password Strength Checker - JavaScript Exercise #17

React Password Strength Checker - JavaScript Exercise #17

Build a React Password Strength Checker Component

Mar 14, 2023ยท

5 min read

Overview

In this exercise, you will create a React component that checks the strength of a password and displays the result to the user. The component will take user input and use a set of rules to determine the strength of the password.

Instructions

  1. Create a new React component called PasswordStrengthChecker.

  2. Create a state variable called password and initialize it to an empty string.

  3. Create a function called checkPasswordStrength that takes in the password as an argument and returns a string indicating the strength of the password based on a set of rules. For example, you might have rules that check for minimum length, use of uppercase and lowercase letters, numbers, and special characters.

  4. Render an input field and a label for the password.

  5. Add an event listener to the input field that updates the state variable "password" whenever the user types in the field.

  6. Call the checkPasswordStrength function with the current value of "password" and display the result to the user.

  7. Style the result so that it is visually distinguishable based on the strength of the password. For example, you might use different colors or font styles to indicate weak, medium, and strong passwords.

Bonus Requirements

  1. Add additional password strength rules, such as checking for the use of dictionary words or common patterns.

  2. Display a password strength meter that visually represents the strength of the password using a color coded bar or another visual element.

  3. Add a button that generates a random password and sets it as the value of the input field.

  4. Implement a feature that checks the strength of the password as the user types, updating the strength indicator in real time.

Before you dive into the final output, I want to encourage you to take some time to work through the exercise yourself. I believe that active learning is the most effective way to learn and grow as a developer.

So, grab a pen and paper, fire up your code editor, and get ready to dive into the React Password Strength Checker exercise. Once you have completed the exercise, feel free to return to this blog post to compare your solution to mine.

Output for the Password Strength Checker exercise

import React, { useState } from 'react';

const PasswordStrengthChecker = () => {
  const [password, setPassword] = useState('');

  const checkPasswordStrength = (password) => {
    let strength = '';
    let color = '';

    // Check for minimum length
    if (password.length < 8) {
      strength = 'Weak';
      color = 'red';
    }
    // Check for use of uppercase and lowercase letters, numbers, and special characters
    else if (!password.match(/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$/)) {
      strength = 'Medium';
      color = 'orange';
    }
    else {
      strength = 'Strong';
      color = 'green';
    }

    return <span style={{ color }}>{strength}</span>;
  };

  const handleInputChange = (event) => {
    setPassword(event.target.value);
  };

  const generateRandomPassword = () => {
    const randomChars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*()';
    let randomPassword = '';
    for (let i = 0; i < 10; i++) {
      randomPassword += randomChars.charAt(Math.floor(Math.random() * randomChars.length));
    }
    setPassword(randomPassword);
  };

  return (
    <div>
      <label htmlFor="password">Password</label>
      <input type="password" id="password" value={password} onChange={handleInputChange} />

      <p>Password strength: {checkPasswordStrength(password)}</p>

      <button onClick={generateRandomPassword}>Generate random password</button>
    </div>
  );
};

export default PasswordStrengthChecker;

This implementation includes:

  • A state variable password that holds the current value of the input field.

  • A function checkPasswordStrength that takes the current password as input and returns a string indicating the strength of the password based on a set of rules.

  • An input field that updates the password state variable whenever the user types in the field.

  • A password strength indicator that displays the result of the checkPasswordStrength function, with the color of the indicator changing based on the strength of the password.

  • A button that generates a random password and sets it as the value of the input field.

import React from 'react';
import PasswordStrengthChecker from './PasswordStrengthChecker';

const App = () => {
  return (
    <div>
      <h1>Password Strength Checker Example</h1>
      <PasswordStrengthChecker />
    </div>
  );
};

export default App;

The React Password Strength Checker component can be used in a variety of applications where password security is important. Here are a few examples:

  1. Authentication Systems: The component can be used in login and sign-up pages to ensure that users create secure passwords that meet certain requirements.

  2. E-commerce Platforms: The component can be used during the checkout process to encourage users to create strong passwords for their accounts.

  3. Banking and Financial Systems: The component can be used in online banking and financial applications to ensure that users create secure passwords that protect their sensitive financial information.

  4. Healthcare Applications: The component can be used in healthcare applications to ensure that users create strong passwords that protect their personal health information.

  5. Education Platforms: The component can be used in education platforms to ensure that students and teachers create secure passwords that protect their personal information and coursework.

  6. Government Applications: The component can be used in government applications that require users to create strong passwords for accessing sensitive information.

In general, any application that requires users to create and use passwords can benefit from a password strength checker component to ensure that users are creating secure passwords that meet certain requirements.

React Password Strength Checker exercise provides a useful example of how to implement a password strength checker component in a React application. By using React hooks, regular expressions, and inline styling, we were able to create a functional and user-friendly component that helps ensure users create strong and secure passwords.

However, it's important to remember that password security is just one aspect of overall security in an application. Developers should also implement other security measures, such as multi-factor authentication and access controls, and users should be educated on best practices for creating and managing passwords.

Overall, the React Password Strength Checker exercise is a good way to practice your React skills and learn more about implementing useful components in your applications. By building on this exercise and exploring other security measures, we can help create more secure and reliable applications for users.

Thanks for taking this JavaScript exercise!

I hope you found this exercise helpful and enjoyable, and that it has deepened your understanding of React development. Keep practising and experimenting with React, and you'll be well on your way to becoming a skilled React developer!

If you have any questions or comments, feel free to reach out to me on Twitter(@rajeshtomjoe), or follow me for more updates.

And if you'd like to receive more exercise on JavaScript, be sure to subscribe to my blog.

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