1. Build a Counter with React Hooks
Challenge: Write a simple React component that keeps track of how many times a button is clicked. Every time the button is pressed, the number should increase.
Task: Implement this using the useState
hook.
import React, { useState } from 'react';
const Counter = () => {
const [count, setCount] = useState(0);
return (
<div>
<p>You clicked {count} times</p>
<button onClick={() => setCount(count + 1)}>
Click me
</button>
</div>
);
};
export default Counter;
Why This Matters: This is one of the most basic examples of state management in React. It demonstrates how to store, update, and display dynamic values with ease using hooks.
Pro Tip: How would you add a "Reset" button to set the count back to 0? Try it out!
2. Create a Form to Capture User Input
Challenge: Implement a form with two input fields—name
and email
. The values should update dynamically as the user types, and when the form is submitted, the entered data should appear on the screen.
import React, { useState } from 'react';
const UserForm = () => {
const [formData, setFormData] = useState({
name: '',
email: ''
});
const handleChange = (e) => {
const { name, value } = e.target;
setFormData((prevData) => ({ ...prevData, [name]: value }));
};
return (
<form>
<input
type="text"
name="name"
value={formData.name}
onChange={handleChange}
placeholder="Name"
/>
<input
type="email"
name="email"
value={formData.email}
onChange={handleChange}
placeholder="Email"
/>
<button type="submit">Submit</button>
</form>
);
};
export default UserForm;
Why This Matters: Handling form input in React is a critical skill, especially for applications requiring user interactions, like login forms or search fields.
Pro Tip: How could you handle validation to ensure the email format is correct before allowing the form to submit?
3. Build a To-Do List with Add and Remove Functionality
Challenge: Create a to-do list where users can add tasks by typing into an input field and pressing "Add." Each task should have a "Remove" button to delete the task.
import React, { useState } from 'react';
const TodoList = () => {
const [todos, setTodos] = useState([]);
const [newTodo, setNewTodo] = useState('');
const addTodo = () => {
if (newTodo.trim()) {
setTodos([...todos, newTodo]);
setNewTodo('');
}
};
const removeTodo = (index) => {
setTodos(todos.filter((_, i) => i !== index));
};
return (
<div>
<input
type="text"
value={newTodo}
onChange={(e) => setNewTodo(e.target.value)}
placeholder="Add a new task"
/>
<button onClick={addTodo}>Add</button>
<ul>
{todos.map((todo, index) => (
<li key={index}>
{todo} <button onClick={() => removeTodo(index)}>Remove</button>
</li>
))}
</ul>
</div>
);
};
export default TodoList;
Why This Matters: Managing lists and state updates is a common task in React applications, especially for building dynamic user interfaces.
Pro Tip: What happens if you try to add an empty to-do item? How would you prevent that?
4. Implement Debouncing in a Search Input
Challenge: Build a search input that waits 500ms after the user stops typing before performing a search (simulated by updating the state). Use useEffect
for this.
import React, { useState, useEffect } from 'react';
const Search = () => {
const [query, setQuery] = useState('');
const [searchTerm, setSearchTerm] = useState('');
useEffect(() => {
const timeoutId = setTimeout(() => {
setSearchTerm(query);
}, 500);
return () => clearTimeout(timeoutId);
}, [query]);
return (
<div>
<input
type="text"
value={query}
onChange={(e) => setQuery(e.target.value)}
placeholder="Search..."
/>
<p>Results for: {searchTerm}</p>
</div>
);
};
export default Search;
Why This Matters: Debouncing is essential in search fields to prevent unnecessary API calls, improving performance and user experience.
Pro Tip: How could you improve this by adding a loading indicator while the user types?
5. Toggle Between "Hello" and "Goodbye" Messages
Challenge: Create a component that displays "Hello" or "Goodbye" based on a button toggle. Every time the button is clicked, the message should switch.
import React, { useState } from 'react';
const ToggleMessage = () => {
const [showHello, setShowHello] = useState(true);
return (
<div>
<p>{showHello ? 'Hello' : 'Goodbye'}</p>
<button onClick={() => setShowHello(!showHello)}>
Toggle Message
</button>
</div>
);
};
export default ToggleMessage;
Why This Matters: Conditional rendering is a core part of React's power, and this challenge helps solidify how to change what’s displayed based on state.
Pro Tip: How would you modify this so that it displays "Hello" in blue and "Goodbye" in red?
Bonus Challenge for the Curious:
For each of these components, how would you refactor the logic to separate concerns and make the code more reusable? Consider creating custom hooks where appropriate!
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