Create async await

Chapter 12/async await

@@ -0,0 +1,17 @@
+    let cnt = 0;
+    function outputTime(val) {
+        return new Promise(resolve => {
+            setTimeout(() => {
+                cnt++;
+                resolve(`x value ${val} counter:${cnt}`);
+            }, 1000);
+        });
+    }
+    async function aCall(val) {
+        console.log(`ready ${val} counter:${cnt}`);
+        const res = await outputTime(val);
+        console.log(res);
+    }
+    for (let x = 1; x < 4; x++) {
+        aCall(x);
+    }