Add tasks

Author: tshemsedinov

JavaScript/Tasks/1-async.js

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+'use strict';
+
+// Task: rewrite `total` from callbacks contract to async/await
+// Hint: do not forget to catch errors with try/catch block
+
+const total = (items, callback) => {
+  let result = 0;
+  for (const item of items) {
+    if (item.price < 0) {
+      callback(new Error('Negative price is not allowed'));
+      return;
+    }
+    result += item.price;
+  }
+  callback(null, result);
+};
+
+const electronics = [
+  { name: 'Laptop', price: 1500 },
+  { name: 'Keyboard', price: 100 },
+  { name: 'HDMI cable', price: 10 },
+];
+
+total(electronics, (error, money) => {
+  if (error) console.error({ error });
+  else console.log({ money });
+});

JavaScript/Tasks/2-method.js

@@ -0,0 +1,35 @@
+'use strict';
+
+// Task: rewrite `total` method from callbacks to async method
+
+class Basket {
+  #items = null;
+
+  constructor(items) {
+    this.#items = items;
+  }
+
+  total(callback) {
+    let result = 0;
+    for (const item of this.#items) {
+      if (item.price < 0) {
+        callback(new Error('Negative price is not allowed'));
+        return;
+      }
+      result += item.price;
+    }
+    callback(null, result);
+  }
+}
+
+const electronics = [
+  { name: 'Laptop', price: 1500 },
+  { name: 'Keyboard', price: 100 },
+  { name: 'HDMI cable', price: 10 },
+];
+
+const basket = new Basket(electronics);
+basket.total((error, money) => {
+  if (error) console.error({ error });
+  else console.log({ money });
+});