How to Use await Inside Loop in Flutter

Flutter async programming can be confusing for beginners. This is because it uses a single-threaded model. That is, all operations have to be completed on the same thread. However, Flutter offers asynchronous programming with futures, async, and await keywords.

If you come from a JavaScript background, async/await is probably familiar to you. If not, don’t worry, it’s not that complicated. The await keyword can only be used inside an async function. When used, it causes the program to pause at that line until the Future returns a value.

Here are a few examples about how to use await keyword inside a loop:

for (var item in myList) {
  await callOther(item);
}

await Future.forEach(myList, (item) async {
  await anotherFutureFunction(item);
});

await searchRead(saleTable, args, params).then((items) async {
  for (var i = 0; i < items.length; i++) {
    Sale sale = Sale.fromJson(items[i]);
    sale.product = await searchProductById(sale.product_id);
  }
})