Asynchronous Programming
- Asynchronous Programming and Callbacks: Mastering asynchronous programming concepts and callbacks is crucial for handling non-blocking I/O operations effectively.
// asynchronous operation with a callback
function fetchData(callback) {
setTimeout(() => {
callback("Data received");
}, 1000);
}
fetchData((data) => {
console.log(data); // Output: Data received
});
- Timers: Understanding timers allows you to schedule and execute code asynchronously at specified intervals.
// using setTimeout to execute code after a delay
setTimeout(() => {
console.log("Delayed message");
}, 2000);
//using setInterval to execute code repeatedly
setInterval(() => {
console.log("Repeated message");
}, 1000);
- Promises: Learning about promises simplifies asynchronous code management and error handling.
// using a Promise to handle asynchronous operation
function fetchData() {
return new Promise((resolve, reject) => {
setTimeout(() => {
resolve("Data received");
}, 1000);
});
}
fetchData().then((data) => {
console.log(data); // Output: Data received
});
- Async and Await: Utilizing async/await syntax simplifies asynchronous code execution and improves readability.
// using async/await to handle asynchronous operation
async function fetchData() {
return new Promise((resolve) => {
setTimeout(() => {
resolve("Data received");
}, 1000);
});
}
async function processData() {
const data = await fetchData();
console.log(data); // Output: Data received
}
processData();
- Closure: Understanding closures enables you to create and manage encapsulated state within asynchronous functions.
// using closures in asynchronous function
function counter() {
let count = 0;
return function() {
return ++count;
};
}
const increment = counter();
setTimeout(() => {
console.log(increment()); // Output: 1
}, 1000);
setTimeout(() => {
console.log(increment()); // Output: 2
}, 2000);
How much JavaScript do you need to know to use Node.js?
NodeJS has revolutionized web development by enabling developers to create powerful server-side applications using JavaScript. If you’re new to NodeJS, you might wonder how much JavaScript knowledge you need to get started. In this guide, we’ll explore the essential JavaScript skills required to dive into NodeJS and build robust applications.
Table of Content
- JavaScript Fundamental
- Asynchronous Programming
- NodeJS specific Concepts
- Conclusion