Can you give me an example of using promises in TypeScript?

Can you give me an example of using promises in TypeScript?

Sure! Here's a simple example of a promise in TypeScript:

function fetchData(): Promise<string> {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            const data = 'Hello, World!';
            resolve(data);
        }, 1000);
    });
}

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

What does the resolve function do in this example?

The resolve function is called when the asynchronous operation is successful. It sends the result back to the caller.

Can I handle errors with promises?

Yes, you can handle errors using the reject function. You can chain a .catch() method to handle any errors that occur.

Can you show me how to handle errors in the promise?

Absolutely! Here's how you can handle errors:

function fetchDataWithError(): Promise<string> {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            const errorOccurred = true;
            if (errorOccurred) {
                reject('Error fetching data');
            } else {
                resolve('Data fetched successfully');
            }
        }, 1000);
    });
}

fetchDataWithError()
    .then(data => console.log(data))
    .catch(error => console.error(error));