What are the differences between callback functions and promises?

What are the differences between callback functions and promises in JavaScript?

Callback functions are functions passed as arguments to other functions, while promises are objects that represent the eventual completion or failure of an asynchronous operation.

Can you give me an example of a callback function?

Sure! Here's a simple example:

function fetchData(callback) {
    setTimeout(() => {
        callback('Data received!');
    }, 1000);
}

fetchData((data) => {
    console.log(data);
});

How about an example of a promise?

Absolutely! Here's how you can use a promise:

function fetchData() {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            resolve('Data received!');
        }, 1000);
    });
}

fetchData().then(data => {
    console.log(data);
});

Which one is better to use?

Promises are generally preferred over callbacks because they help avoid callback hell and make the code more readable and manageable.