Add async/await ecamples

Author: tshemsedinov

JavaScript/6-async.js

@@ -0,0 +1,25 @@
+'use strict';
+
+const sum = async (a, b) => {
+  if (typeof(a) === 'number' && typeof(b) === 'number') {
+    return a + b;
+  } else {
+    return Promise.reject(new Error('a and b should be numbers'));
+  }
+};
+
+sum(2, 3)
+  .then(data => {
+    console.log(data);
+  })
+  .catch(err => {
+    console.log(err.message);
+  });
+
+sum(7, 'A')
+  .then(data => {
+    console.log(data);
+  })
+  .catch(err => {
+    console.log(err.message);
+  });

JavaScript/7-await.js

@@ -0,0 +1,25 @@
+'use strict';
+
+const sum = async (a, b) => {
+  if (typeof(a) === 'number' && typeof(b) === 'number') {
+    return a + b;
+  } else {
+    return Promise.reject(new Error('a and b should be numbers'));
+  }
+};
+
+(async () => {
+
+  try {
+    console.log(await sum(2, 3));
+  } catch (e) {
+    console.log(e.message);
+  }
+
+  try {
+    console.log(await sum(7, 'A'));
+  } catch (e) {
+    console.log(e.message);
+  }
+
+})();