CODING EXERCISES TEST YOUR SKILLS
Asynchronous JavaScript Coding Exercises
🌈 Dive Deep into Asynchronous JavaScript with Our Latest Coding Exercises! 🚀
Unlock the power of asynchronous programming in JavaScript with our collection of 10 engaging coding exercises. From mastering callbacks and promises to leveraging the elegant async/await syntax, these exercises are designed to equip you with the skills needed to write efficient, non-blocking JavaScript code.
Perfect for both beginners and seasoned developers, these exercises come with detailed explanations and complete code samples, ensuring a comprehensive learning experience.
#JavaScript #AsynchronousProgramming #WebDevelopment #CodingExercises #AsyncAwait #Promises #TechLearning
Let’s make our web applications more responsive and faster by mastering asynchronous JavaScript. Share your thoughts or questions below, and let’s engage in a productive discussion. Happy coding! 🎉
Exercise 1: Basic Callback Function
Objective: Understand how to use a callback function to handle asynchronous operations.
function fetchData(callback) {
setTimeout(() => { // Simulates fetching data from an API
callback(‘Data fetched’);
}, 1000);
}
fetchData((data) => {
console.log(data); // Expected output: Data fetched
});
Explanation: Demonstrates the basic usage of a callback function to handle data that is fetched asynchronously.
Exercise 2: Promise Basics
Objective: Learn to create and use a Promise to handle asynchronous operations.
function fetchData() {
return new Promise((resolve, reject) => {
setTimeout(() => resolve(‘Data fetched’), 1000);
});
}
fetchData().then(data => console.log(data)); // Expected output: Data fetched
Explanation: Introduces the concept of Promises as a way to handle asynchronous tasks, using resolve to handle successful operations.
Exercise 3: Handling Promise Rejection
Objective: Learn to handle errors in Promises using catch.
function fetchData() {
return new Promise((resolve, reject) => {
setTimeout(() => reject(‘Error fetching data’), 1000);
});
}
fetchData().then(data => console.log(data)).catch(error => console.error(error)); // Expected output: Error fetching data
Explanation: Teaches error handling in Promises with catch, providing a mechanism to handle rejected promises.
Exercise 4: Chaining Promises
Objective: Understand how to chain Promises for sequential asynchronous operations.
function firstTask() {
return new Promise(resolve => setTimeout(() => resolve(‘First task completed’), 1000));
}
function secondTask() {
return new Promise(resolve => setTimeout(() => resolve(‘Second task completed’), 1000));
}
firstTask().then(result => {
console.log(result);
return secondTask();
}).then(result => console.log(result));
Explanation: Demonstrates chaining multiple promises to ensure that asynchronous operations are completed in sequence.
Exercise 5: Async/Await Basic
Objective: Use async and await to handle asynchronous operations more intuitively.
async function fetchData() {
return ‘Data fetched’;
}
async function run() {
const data = await fetchData();
console.log(data); // Expected output: Data fetched
}
run();
Explanation: Introduces async/await syntax as a cleaner and more readable way to handle asynchronous operations compared to Promises and callbacks.
Exercise 6: Error Handling with Async/Await
Objective: Learn to handle errors in asynchronous functions using try/catch.
async function fetchData() {
throw ‘Error fetching data’;
}
async function run() {
try {
const data = await fetchData();
console.log(data);
} catch (error) {
console.error(error); // Expected output: Error fetching data
}
}
run();
Explanation: Teaches error handling in async/await syntax using try/catch blocks to catch and handle errors in asynchronous operations.
Exercise 7: Using Promise.all
Objective: Execute multiple asynchronous operations in parallel and handle their results together.
function fetchData1() {
return new Promise(resolve => setTimeout(() => resolve(‘Data 1 fetched’), 1000));
}
function fetchData2() {
return new Promise(resolve => setTimeout(() => resolve(‘Data 2 fetched’), 2000));
}
async function run() {
const [data1, data2] = await Promise.all([fetchData1(), fetchData2()]);
console.log(data1, data2); // Expected output: Data 1 fetched Data 2 fetched
}
run();
Explanation: Shows how to use Promise.all to efficiently handle multiple promises by running them in parallel and waiting for all of them to complete.
Exercise 8: Async/Await with Fetch API
Objective: Fetch data from an API using async/await and the Fetch API.
async function fetchData() {
const response = await fetch(‘https://api.example.com/data’);
const data = await response.json();
console.log(data);
}
fetchData();
Explanation: Combines async/await with the Fetch API to perform asynchronous HTTP requests in a clean and readable way.
Exercise 9: Custom Async Iterator
Objective: Create a custom asynchronous iterator to iterate over data asynchronously.
async function* asyncGenerator() {
let i = 0;
while(i < 3) {
yield await new Promise(resolve => setTimeout(() => resolve(i++), 1000));
}
}
async function run() {
for await (let num of asyncGenerator()) {
console.log(num); // Expected output: 0 1 2
}
}
run();
Explanation: Introduces asynchronous generators and for await…of loops to handle asynchronous iteration, useful for processing streams of data.
Exercise 10: Handling Multiple Fetch Requests
Objective: Fetch multiple URLs in parallel and process the data once all requests are completed.
async function fetchData(urls) {
const promises = urls.map(url => fetch(url).then(response => response.json()));
return Promise.all(promises);
}
const urls = [‘https://api.example.com/data1’, ‘https://api.example.com/data2’];
fetchData(urls).then(data => console.log(data));
Explanation: Demonstrates handling multiple asynchronous fetch requests in parallel using Promise.all, a common pattern in web development for working with multiple API endpoints.
CODE EXERCISE Asynchronous JavaScript Coding Exercises
CODING EXERCISES TEST YOUR SKILLS
Asynchronous JavaScript Coding Exercises
🌈 Dive Deep into Asynchronous JavaScript with Our Latest Coding Exercises! 🚀
Unlock the power of asynchronous programming in JavaScript with our collection of 10 engaging coding exercises. From mastering callbacks and promises to leveraging the elegant async/await syntax, these exercises are designed to equip you with the skills needed to write efficient, non-blocking JavaScript code.
Perfect for both beginners and seasoned developers, these exercises come with detailed explanations and complete code samples, ensuring a comprehensive learning experience.
#JavaScript #AsynchronousProgramming #WebDevelopment #CodingExercises #AsyncAwait #Promises #TechLearning
Let’s make our web applications more responsive and faster by mastering asynchronous JavaScript. Share your thoughts or questions below, and let’s engage in a productive discussion. Happy coding! 🎉
Exercise 1: Basic Callback Function
Objective: Understand how to use a callback function to handle asynchronous operations.
function fetchData(callback) {
setTimeout(() => { // Simulates fetching data from an API
callback(‘Data fetched’);
}, 1000);
}
fetchData((data) => {
console.log(data); // Expected output: Data fetched
});
Explanation: Demonstrates the basic usage of a callback function to handle data that is fetched asynchronously.
Exercise 2: Promise Basics
Objective: Learn to create and use a Promise to handle asynchronous operations.
function fetchData() {
return new Promise((resolve, reject) => {
setTimeout(() => resolve(‘Data fetched’), 1000);
});
}
fetchData().then(data => console.log(data)); // Expected output: Data fetched
Explanation: Introduces the concept of Promises as a way to handle asynchronous tasks, using resolve to handle successful operations.
Exercise 3: Handling Promise Rejection
Objective: Learn to handle errors in Promises using catch.
function fetchData() {
return new Promise((resolve, reject) => {
setTimeout(() => reject(‘Error fetching data’), 1000);
});
}
fetchData().then(data => console.log(data)).catch(error => console.error(error)); // Expected output: Error fetching data
Explanation: Teaches error handling in Promises with catch, providing a mechanism to handle rejected promises.
Exercise 4: Chaining Promises
Objective: Understand how to chain Promises for sequential asynchronous operations.
function firstTask() {
return new Promise(resolve => setTimeout(() => resolve(‘First task completed’), 1000));
}
function secondTask() {
return new Promise(resolve => setTimeout(() => resolve(‘Second task completed’), 1000));
}
firstTask().then(result => {
console.log(result);
return secondTask();
}).then(result => console.log(result));
Explanation: Demonstrates chaining multiple promises to ensure that asynchronous operations are completed in sequence.
Exercise 5: Async/Await Basic
Objective: Use async and await to handle asynchronous operations more intuitively.
async function fetchData() {
return ‘Data fetched’;
}
async function run() {
const data = await fetchData();
console.log(data); // Expected output: Data fetched
}
run();
Explanation: Introduces async/await syntax as a cleaner and more readable way to handle asynchronous operations compared to Promises and callbacks.
Exercise 6: Error Handling with Async/Await
Objective: Learn to handle errors in asynchronous functions using try/catch.
async function fetchData() {
throw ‘Error fetching data’;
}
async function run() {
try {
const data = await fetchData();
console.log(data);
} catch (error) {
console.error(error); // Expected output: Error fetching data
}
}
run();
Explanation: Teaches error handling in async/await syntax using try/catch blocks to catch and handle errors in asynchronous operations.
Exercise 7: Using Promise.all
Objective: Execute multiple asynchronous operations in parallel and handle their results together.
function fetchData1() {
return new Promise(resolve => setTimeout(() => resolve(‘Data 1 fetched’), 1000));
}
function fetchData2() {
return new Promise(resolve => setTimeout(() => resolve(‘Data 2 fetched’), 2000));
}
async function run() {
const [data1, data2] = await Promise.all([fetchData1(), fetchData2()]);
console.log(data1, data2); // Expected output: Data 1 fetched Data 2 fetched
}
run();
Explanation: Shows how to use Promise.all to efficiently handle multiple promises by running them in parallel and waiting for all of them to complete.
Exercise 8: Async/Await with Fetch API
Objective: Fetch data from an API using async/await and the Fetch API.
async function fetchData() {
const response = await fetch(‘https://api.example.com/data’);
const data = await response.json();
console.log(data);
}
fetchData();
Explanation: Combines async/await with the Fetch API to perform asynchronous HTTP requests in a clean and readable way.
Exercise 9: Custom Async Iterator
Objective: Create a custom asynchronous iterator to iterate over data asynchronously.
async function* asyncGenerator() {
let i = 0;
while(i < 3) {
yield await new Promise(resolve => setTimeout(() => resolve(i++), 1000));
}
}
async function run() {
for await (let num of asyncGenerator()) {
console.log(num); // Expected output: 0 1 2
}
}
run();
Explanation: Introduces asynchronous generators and for await…of loops to handle asynchronous iteration, useful for processing streams of data.
Exercise 10: Handling Multiple Fetch Requests
Objective: Fetch multiple URLs in parallel and process the data once all requests are completed.
async function fetchData(urls) {
const promises = urls.map(url => fetch(url).then(response => response.json()));
return Promise.all(promises);
}
const urls = [‘https://api.example.com/data1’, ‘https://api.example.com/data2’];
fetchData(urls).then(data => console.log(data));
Explanation: Demonstrates handling multiple asynchronous fetch requests in parallel using Promise.all, a common pattern in web development for working with multiple API endpoints.