update

async-await/0_callbacks.js

@@ -43,7 +43,7 @@ function entryPoint () {
 
     Callbacks are usually meant for asynchronous programming. When
     we meet a function that accepts a callback, it is likely an
-    asynchronous function, such as time, such as
+    asynchronous function, such as
     setTimeout(callback, delay).
 
     Callbacks are not asynchronous by nature, but can be used 

async-await/3_async-await.js

@@ -0,0 +1,60 @@
+// https://javascript.info/async-await
+
+// An async function always returns a promise. Other values are wrapped in a resolved promise automatically.
+// Async and await are merely syntactic sugar in order to make Promise usage easier
+
+async function f1 () {
+    return 1;
+}
+  
+f1().then(console.log); // 1
+  
+// The keyword await makes JavaScript wait until that promise settles and returns its result.
+// It can be used in async functions only.
+// Let’s emphasize: await literally suspends the function execution until the promise settles,
+// and then resumes it with the promise result.
+async function f2 () {
+  const promise = new Promise((resolve, reject) => {
+    setTimeout(() => resolve('done!'), 1000);
+  });
+  const result = await promise; // wait until the promise resolves (*)
+  console.log(result); // "done!"
+}
+f2();
+
+// The code in the same function after "await"
+// is to be intended in the "then()" of the primise. This means
+// that after await (but before the completion of the Promise),
+// the flow of execution goes out that code block. For example
+// consider the following example:
+async function exampleAsyncFunction () {
+  console.log('Before await');
+  await new Promise(function (resolve, reject) {
+    setTimeout(() => resolve('done'), 500);
+  }); // Pauses execution here until the promise resolves.
+  console.log('After await');
+}
+console.log('Start');
+exampleAsyncFunction();
+console.log('End');
+
+// The result will be:
+//  Start, Before Await, End, After await
+// "End" comes before "After Await" because the
+// flow of execution goes to the caller
+// when await is invoked.
+
+// Questions
+//
+// Why await only works in async function in javascript?
+// https://stackoverflow.com/questions/49640647/why-await-only-works-in-async-function-in-javascript
+//
+// Why using async-await
+// https://stackoverflow.com/questions/42624647/why-use-async-when-i-have-to-use-await
+//
+// Be mindful: it is not possible to create an async function from scratch (such as
+// setInterval o fetch)
+// https://stackoverflow.com/questions/61857274/how-to-create-custom-asynchronous-function-in-javascript
+//
+// Another question that may be interesting
+// https://stackoverflow.com/questions/42624647/why-use-async-when-i-have-to-use-await

async-await/sincrono_vs_asincrono.txt

@@ -4,9 +4,9 @@ https://stackoverflow.com/questions/7131991/asynchronous-and-synchronous-terms
 
 La parola "sincrono" in contesto informatico vuol dire "sincronizzato", ovvero
 il chiamante deve aspettare la risposta del chiamato, mentre
-"async" vuol dire "non sincronizzato". 
+"async" vuol dire "non sincronizzato".
-Ciò vuol dire sincronizzato (o NON sincronizzato) con altre porzioni di codice.
+Ciò vuol dire (non)/sincronizzato con altre porzioni di codice.
-La definizione da dizionario invece differisce. 
+La definizione da dizionario invece differisce.
 Per Treccani: "Sincrono: Che avviene nello stesso momento",
 mentre sappiamo che un'operazione sincrona rispetto ad un'altra
 non avviene allo stesso tempo.