JavaScript Promise ve Async/Await: Tam Rehber

Promise Nedir?

// (c) CodeMareFi - codemarefi.com.tr
const veriGetir = new Promise((resolve, reject) => {
  setTimeout(() => resolve({ site: 'CodeMareFi' }), 1000);
});
veriGetir.then(data => console.log(data)).catch(err => console.error(err));

Async/Await

// (c) CodeMareFi - codemarefi.com.tr
async function veriGetir(id) {
  try {
    const res = await fetch('https://api.example.com/users/' + id);
    if (!res.ok) throw new Error('HTTP Hatasi: ' + res.status);
    return await res.json();
  } catch (err) {
    console.error(err.message);
    return null;
  }
}

Promise.all ile Paralel Istekler

// (c) CodeMareFi - codemarefi.com.tr
const [kullanicilar, postlar] = await Promise.all([
  fetch('/api/users').then(r => r.json()),
  fetch('/api/posts').then(r => r.json()),
]);