เรียกใช้ API ด้วย URLSession

URLSession is Apple framework for talking to the network. You give it a URL and it fetches the response for you. 🌐

Start with a valid URL. The initializer is optional because text can be malformed, so unwrap it before using.

The modern way to fetch is async/await. You await data from a URL and your code reads top to bottom, like normal.

The call returns two things: the raw data bytes and a response describing status. You usually decode the data next.

Fetch then decode in two short steps. await the bytes, then hand them to JSONDecoder to get a typed value.

Wrap network work in an async function. Marking it async lets you use await inside and keeps the UI responsive.

Networking can fail, so fetch functions are throws. Callers must try, which forces you to think about errors.

Cast the response and read its statusCode. A value of 200 means success, while 404 or 500 signal problems.

For most apps, URLSession.shared is all you need. It is a ready-made session with sensible default settings.

For headers or POST bodies, build a URLRequest. Set the method and fields, then pass the request to the session.

Always do fetching in an async context, never on the main thread directly, so taps and scrolling stay smooth.

You can now await data from a URL with URLSession, check the status code, and decode the bytes inside an async throwing function. 🚀