diff --git a/JavaScript/1-sync-try.js b/JavaScript/1-sync-try.js
index 69a12ad..0121245 100644
--- a/JavaScript/1-sync-try.js
+++ b/JavaScript/1-sync-try.js
@@ -7,18 +7,20 @@ const sum = (a, b) => {
   throw new Error('a and b should be numbers');
 };
 
+const x = 2;
+const y = 3;
 try {
-  console.log(sum(2, 3));
+  const total = sum(x, y);
+  console.log({ x, y, total });
 } catch (err) {
-  console.log(err.message);
+  console.error({ x, y, err });
 }
 
+const z = 7;
+const c = 'A';
 try {
-  console.log(sum(7, 'A'));
+  const res = sum(z, c);
+  console.log({ z, c, res });
 } catch (err) {
-  console.log(err.message);
+  console.error({ z, c, err });
 }
-
-console.log(sum(7, 'A'));
-
-console.log('Not executed');
diff --git a/JavaScript/2-sync-tuple.js b/JavaScript/2-sync-tuple.js
index 7be00ad..84e8041 100644
--- a/JavaScript/2-sync-tuple.js
+++ b/JavaScript/2-sync-tuple.js
@@ -7,6 +7,18 @@ const sum = (a, b) => {
   return [new Error('a and b should be numbers')];
 };
 
-console.log(sum(2, 3));
+{
+  const x = 2;
+  const y = 3;
+  const [err, total] = sum(x, y);
+  if (err) console.error({ x, y, err, total });
+  else console.log({ x, y, err, total });
+}
 
-console.log(sum(7, 'A'));
+{
+  const z = 7;
+  const c = 'A';
+  const [err, res = NaN] = sum(z, c);
+  if (err) console.error({ z, c, err, res });
+  else console.log({ z, c, err, res });
+}
diff --git a/JavaScript/3-async.js b/JavaScript/3-async.js
index 9cf4c3b..f97be2c 100644
--- a/JavaScript/3-async.js
+++ b/JavaScript/3-async.js
@@ -8,18 +8,22 @@ const sum = (a, b, callback) => {
   }
 };
 
-sum(2, 3, (err, result) => {
+const x = 2;
+const y = 3;
+sum(x, y, (err, total) => {
   if (err) {
-    console.log(err.message);
+    console.error({ x, y, err });
     return;
   }
-  console.log(result);
+  console.log({ x, y, total });
 });
 
-sum(7, 'A', (err, result) => {
+const z = 7;
+const c = 'A';
+sum(z, c, (err, res) => {
   if (err) {
-    console.log(err.message);
+    console.error({ z, c, err });
     return;
   }
-  console.log(result);
+  console.log({ z, c, res });
 });
diff --git a/JavaScript/4-uncaught.js b/JavaScript/4-uncaught.js
index d3ef3c0..ece17bb 100644
--- a/JavaScript/4-uncaught.js
+++ b/JavaScript/4-uncaught.js
@@ -12,5 +12,16 @@ const sum = (a, b) => {
   throw new Error('a and b should be numbers');
 };
 
-console.log(sum(2, 3));
-console.log(sum(7, 'A'));
+{
+  const x = 2;
+  const y = 3;
+  const total = sum(x, y);
+  console.log({ x, y, total });
+}
+
+{
+  const z = 7;
+  const c = 'A';
+  const res = sum(z, c);
+  console.log({ z, c, res });
+}
diff --git a/JavaScript/5-promise.js b/JavaScript/5-promise.js
index 09bed09..aed9756 100644
--- a/JavaScript/5-promise.js
+++ b/JavaScript/5-promise.js
@@ -1,33 +1,37 @@
 'use strict';
 
-const sum = (a, b) => new Promise((resolve, reject) => {
+const sum = (a, b) => new Promise((totalolve, reject) => {
   if (typeof a === 'number' && typeof b === 'number') {
-    resolve(a + b);
+    totalolve(a + b);
   } else {
     reject(new Error('a and b should be numbers'));
   }
 });
 
-sum(2, 3)
-  .then((data) => {
-    console.log(data);
+const x = 2;
+const y = 3;
+sum(x, y)
+  .then((total) => {
+    console.log({ x, y, total });
   })
   .catch((err) => {
-    console.log(err.message);
+    console.error({ x, y, err });
   });
 
-sum(7, 'A')
-  .then((data) => {
-    console.log(data);
+const z = 7;
+const c = 'A';
+sum(z, c)
+  .then((res) => {
+    console.log({ z, c, res });
   })
   .catch((err) => {
-    console.log(err.message);
+    console.log({ z, c, err });
   });
 
 /*
-sum(7, 'A')
-  .then(data => {
-    console.log(data);
+sum(z, c)
+  .then((res) => {
+    console.log({ z, c, res });
   });
 
 UnhandledPromiseRejectionWarning: Error: a and b should be numbers
diff --git a/JavaScript/6-async-await.js b/JavaScript/6-async-await.js
index 3e69cf0..7b4fa4d 100644
--- a/JavaScript/6-async-await.js
+++ b/JavaScript/6-async-await.js
@@ -9,20 +9,27 @@ const sum = async (a, b) => {
 
 (async () => {
 
+  const x = 2;
+  const y = 3;
   try {
-    console.log(await sum(2, 3));
-  } catch (e) {
-    console.log(e.message);
+    const total = await sum(x, y);
+    console.log({ x, y, total });
+  } catch (err) {
+    console.error({ x, y, err });
   }
 
+  const z = 7;
+  const c = 'A';
   try {
-    console.log(await sum(7, 'A'));
+    const res = await sum(z, c);
+    console.log({ z, c, res });
   } catch (err) {
-    console.log(err.message);
+    console.error({ z, c, err });
   }
 
   /*
-  console.log(await sum(7, 'A'));
+  const res = await sum(z, c);
+  console.log({ z, c, res });
 
   UnhandledPromiseRejectionWarning: Error: a and b should be numbers
 
@@ -30,4 +37,5 @@ const sum = async (a, b) => {
   In the future, promise rejections that are not handled will terminate
   the Node.js process with a non-zero exit code.
   */
+
 })();
diff --git a/JavaScript/7-async-catch.js b/JavaScript/7-async-catch.js
new file mode 100644
index 0000000..2ddfed7
--- /dev/null
+++ b/JavaScript/7-async-catch.js
@@ -0,0 +1,28 @@
+'use strict';
+
+const sum = async (a, b) => {
+  if (typeof a === 'number' && typeof b === 'number') {
+    return a + b;
+  }
+  throw new Error('a and b should be numbers');
+};
+
+(async () => {
+
+  const x = 2;
+  const y = 3;
+  const total = await sum(x, y).catch((err) => {
+    console.error({ x, y, err });
+    return NaN;
+  });
+  console.log({ x, y, total });
+
+  const z = 7;
+  const c = 'A';
+  const res = await sum(z, c).catch((err) => {
+    console.error({ z, c, err });
+    return NaN;
+  });
+  console.log({ z, c, res });
+
+})();
diff --git a/JavaScript/8-promise-all.js b/JavaScript/8-promise-all.js
new file mode 100644
index 0000000..2b56b57
--- /dev/null
+++ b/JavaScript/8-promise-all.js
@@ -0,0 +1,26 @@
+'use strict';
+
+const sum = async (a, b) => {
+  if (typeof a === 'number' && typeof b === 'number') {
+    return a + b;
+  }
+  throw new Error('a and b should be numbers');
+};
+
+(async () => {
+
+  const data = [
+    [2, 3],
+    [7, 'A'],
+  ];
+
+  const [total, result] = await Promise.all(
+    data.map((args) =>
+      sum(...args).catch((err) => {
+        console.error(err);
+      })
+    )
+  );
+  console.log({ total, result });
+
+})();
diff --git a/JavaScript/9-retry.js b/JavaScript/9-retry.js
new file mode 100644
index 0000000..3d0b60e
--- /dev/null
+++ b/JavaScript/9-retry.js
@@ -0,0 +1,28 @@
+'use strict';
+
+const DEFAULT_RETRY = 3;
+
+const httpGet = async ({ url, retry = DEFAULT_RETRY }) => {
+  console.log({ url, retry });
+  const res = await fetch(url).catch(() => ({ ok: false }));
+  if (!res.ok) {
+    const attemptsLeft = retry - 1;
+    if (attemptsLeft > 0) return httpGet({ url, retry: attemptsLeft });
+    throw new Error('Can not get data');
+  }
+  return res.json();
+};
+
+const main = async () => {
+  try {
+    const key = '1f43ea96b1e343fe94333dd2b97a109d';
+    const url = 'https://openexchangerates.org/api/latest.json?app_id=' + key;
+    const data = await httpGet({ url });
+    const rate = data.rates['UAH'];
+    console.log({ rate });
+  } catch (err) {
+    console.error({ err });
+  }
+};
+
+main();