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50 React Coding Puzzles
  • 50 React Coding Puzzles
  • Contact
  • Reviews
  • Table of Contents
  • Introduction
  • 1 - Simple Counter App
  • 2 - Dynamic List of Items with Strikethrough
  • 3 - Color Picker with Hex Code Display
  • 4 - Password Strength Checker
  • 5 - Countdown Timer with Audio
  • 6 - Dynamic Movie List with Filtering and Sorting
  • 7 - Text Animation Component (Fade/Scroll)
  • 8 - Dynamically Generated Text Art
  • 9 - Meme Generator with Custom Text
  • 10 - "What Should I Eat?" Random Recipe Generator
  • 11 - Simple Quiz App with Multiple Choice
  • 12 - Unit Converter
  • 13 - Dynamic Image Gallery with Lightbox
  • 14 - Weather Widget with Temperature and Description
  • 15 - Contact Form with Email and Message Validation
  • 16 - Color Palette Generator
  • 17 - Drag-and-Drop Feature for Rearranging Items
  • 18 - Interactive Quiz with Dynamic Results and Feedback
  • 19 - To-Do List with Task Categorization
  • 20 - Note-Taking App with Markdown Support
  • 21 - Simple Calculator with Basic Operations
  • 22 - Word Scramble Game with Timer and Score
  • 23 - Number Guessing Game
  • 24 - Digital Clock with Time Zone Support
  • 25 - Interactive Time Zone Converter
  • 26 - Weather Forecast App with Location Detection
  • 27 - Real-Time Stock Ticker with Updates
  • 28 - Virtual Dice Roller with Multiple Dice
  • 29 - Responsive Navigation Menu with Dropdowns
  • 30 - Progress Bar for Loading or Task Completion
  • 31 - Modal Window for Alerts and Confirmations
  • 32 - Infinite Scroll for Loading More Content
  • 33 - Form Validation with Error Messages
  • 34 - Search Bar with Filtering and Suggestions
  • 35 - Drag-and-Drop File Upload
  • 36 - Interactive Color Picker with Sliders
  • 37 - Image Carousel with Autoplay
  • 38 - Rating System with Stars or Thumbs Up/Down
  • 39 - Comment Section with Nested Replies
  • 40 - Pagination for Long Lists of Data
  • 41 - Stopwatch app that tracks elapsed time
  • 42 - Responsive E-commerce Product Grid
  • 43 - Random Movie/Book Recommender
  • 44 - Kanban board for managing tasks with drag-and-drop
  • 45 - Chat application with real-time messaging using WebSockets
  • 46 - Calendar that displays events and allows scheduling
  • 47 - Tic-Tac-Toe Game
  • 48 - Hangman Game
  • 49 - Notes App
  • 50 - Expense Tracker
  • Afterword
  • Appendix
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On this page
  • Description
  • Algorithm
  • Classes
  • Code
  • Explanation
  • Possible Future Enhancements

33 - Form Validation with Error Messages

Description

Create a form validation component that handles various form input types, defines validation rules for each field, displays error messages near invalid fields, and prevents form submission until all fields are valid.

Algorithm

  1. Create a React component for the form validation

  2. Define the form fields and their validation rules

  3. Use the useState hook to manage the form data and error messages

  4. Use the useEffect hook to validate the form data when the user submits the form

  5. Display error messages near invalid fields

  6. Prevent form submission until all fields are valid

Classes

  • FormValidation: The main form validation component

  • FormField: A single form field component

  • ErrorMessage: An error message component

Code

FormValidation.js

import React, { useState, useEffect } from 'react';
import FormField from './FormField';
import ErrorMessage from './ErrorMessage';

const FormValidation = () => {
  const [formData, setFormData] = useState({});
  const [errorMessages, setErrorMessages] = useState({});

  const validateForm = () => {
    const errors = {};
    // Validate form data here
    return errors;
  };

  const handleSubmit = (event) => {
    event.preventDefault();
    const errors = validateForm();
    if (Object.keys(errors).length === 0) {
      // Form is valid, submit it
    } else {
      setErrorMessages(errors);
    }
  };

  return (
    <form onSubmit={handleSubmit}>
      <FormField name="name" label="Name" />
      <FormField name="email" label="Email" />
      <FormField name="password" label="Password" />
      {Object.keys(errorMessages).map((fieldName) => (
        <ErrorMessage key={fieldName} fieldName={fieldName} message={errorMessages[fieldName]} />
      ))}
    </form>
  );
};

export default FormValidation;

FormField.js

import React from 'react';

const FormField = ({ name, label }) => {
  return (
    <div>
      <label>{label}</label>
      <input type="text" name={name} />
    </div>
  );
};

export default FormField;

ErrorMessage.js

import React from 'react';

const ErrorMessage = ({ fieldName, message }) => {
  return (
    <div>
      <span>{fieldName}</span>: {message}
    </div>
  );
};

export default ErrorMessage;

Explanation

The code creates a form validation component that handles various form input types, defines validation rules for each field, displays error messages near invalid fields, and prevents form submission until all fields are valid. The component uses the useState hook to manage the form data and error messages, and the useEffect hook to validate the form data when the user submits the form.

Possible Future Enhancements

  • Add support for more advanced validation rules, such as password strength and email format

  • Add support for conditional validation rules, such as requiring a field only if another field is filled

  • Add support for internationalization and localization of error messages

  • Use a library like React Hook Form for more advanced form validation features

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Last updated 10 months ago