Async

Asynchronous programming memungkinkan eksekusi kode tanpa menunggu operasi selesai:

Promises


const fetchData = () => {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      resolve("Data berhasil diambil");
    }, 2000);
  });
};
 
fetchData()
  .then(data => console.log(data))
  .catch(error => console.error(error));

async/await


async function getData() {
  try {
    const response = await fetchData();
    console.log(response);
  } catch (error) {
    console.error(error);
  }
}

Callback Functions


function fetchData(callback) {
  setTimeout(() => {
    callback("Data berhasil diambil");
  }, 2000);
}
 
fetchData(data => console.log(data));

Event Loop

JavaScript menggunakan event loop untuk menangani operasi asynchronous:


console.log("Start");
 
setTimeout(() => {
  console.log("Timeout");
}, 0);
 
console.log("End");
 
// Output:
// Start
// End
// Timeout