revision new files

Chapter 12/asyncawait.js

@@ -0,0 +1,16 @@
+function saySomething(x) {
+    return new Promise(resolve => {
+        setTimeout(() => {
+            resolve('something' + x);
+        }, 2000);
+    });
+}
+
+async function talk(x) {
+    const words = await saySomething(x);
+    console.log(words);
+}
+
+talk(2);
+talk(4);
+talk(8);