Day11.js

// Activity 1: Understanding Promises

// Task 1: Create a promise that resolves with a message after a 2-second timeout and log the message to the console.
const promise1 = new Promise((resolve, reject) => {
    setTimeout(() => {
        resolve("Promise resolved after 2 seconds");
    }, 2000);
});

promise1.then(message => console.log(message));

// Task 2: Create a promise that rejects with an error message after a 2-second timeout and handle the error using .catch().
const promise2 = new Promise((resolve, reject) => {
    setTimeout(() => {
        reject("Promise rejected after 2 seconds");
    }, 2000);
});

promise2.catch(error => console.error(error));

// Activity 2: Chaining Promises

// Task 3: Create a sequence of promises that simulate fetching data from a server. Chain the promises to log messages in a specific order.
const fetchData = (data, delay) => {
    return new Promise((resolve) => {
        setTimeout(() => {
            resolve(data);
        }, delay);
    });
};

fetchData("Data 1", 1000)
    .then(data => {
        console.log(data);
        return fetchData("Data 2", 1000);
    })
    .then(data => {
        console.log(data);
        return fetchData("Data 3", 1000);
    })
    .then(data => {
        console.log(data);
    });

// Activity 3: Using Async/Await

// Task 4: Write an async function that waits for a promise to resolve and then logs the resolved value.
const asyncFunction1 = async () => {
    const message = await promise1;
    console.log(message);
};

asyncFunction1();

// Task 5: Write an async function that handles a rejected promise using try-catch and logs the error message.
const asyncFunction2 = async () => {
    try {
        const message = await promise2;
        console.log(message);
    } catch (error) {
        console.error(error);
    }
};

asyncFunction2();

// Activity 4: Fetching Data from an API

// Task 6: Use the fetch API to get data from a public API and log the response data to the console using promises.
const fetchDataFromAPI1 = () => {
    fetch('https://jsonplaceholder.typicode.com/posts/1')
        .then(response => response.json())
        .then(data => console.log(data))
        .catch(error => console.error('Error:', error));
};

fetchDataFromAPI1();

// Task 7: Use the fetch API to get data from a public API and log the response data to the console using async/await.
const fetchDataFromAPI2 = async () => {
    try {
        const response = await fetch('https://jsonplaceholder.typicode.com/posts/1');
        const data = await response.json();
        console.log(data);
    } catch (error) {
        console.error('Error:', error);
    }
};

fetchDataFromAPI2();

// Activity 5: Concurrent Promises

// Task 8: Use Promise.all to wait for multiple promises to resolve and then log all their values.
const promise3 = fetchData("Promise 3", 1000);
const promise4 = fetchData("Promise 4", 2000);
const promise5 = fetchData("Promise 5", 3000);

Promise.all([promise3, promise4, promise5])
    .then(values => {
        console.log(values);
    });

// Task 9: Use Promise.race to log the value of the first promise that resolves among multiple promises.
Promise.race([promise3, promise4, promise5])
    .then(value => {
        console.log('First resolved promise:', value);
    });