Add more example about Asynchronous Programming

Sample/asynchonous_programming/index.js

@@ -55,3 +55,46 @@ const getNewToDo = async () => {
 getNewToDo().then((data) => {
   console.log(">>> Data: ", data);
 });
+
+const getJSON = (url, errorMsg = "Something went wrong") => {
+  return fetch(url).then((response) => {
+    if (!response.ok) throw new Error(`${errorMsg} (${response.status})`);
+
+    return response.json();
+  });
+};
+
+const printInforCountry = (data) => {
+  console.log(`Native name: ${data.nativeName}`);
+  console.log(`Capital: ${data.capital}`);
+  console.log(`Population: ${data.population}`);
+};
+
+const getCountryData = function (country) {
+  // Country 1
+  getJSON(
+    `https://countries-api-836d.onrender.com/countries/name/${country}`,
+    "Country not found!"
+  )
+    .then((data) => {
+      printInforCountry(data[0]);
+
+      const neighbour = data[0].borders?.[0];
+      if (!neighbour) throw new Error("No neighbour found!");
+      // Country 2
+      return getJSON(
+        `https://countries-api-836d.onrender.com/countries/alpha/${neighbour}`,
+        "Country not found!"
+      );
+    })
+    .then((data) => {
+      console.log(`----------Neighbour Contry-----------`);
+      printInforCountry(data);
+    })
+    .catch((err) => {
+      console.error(`Something went wrong 💥💥 ${err.message}. Try again!`);
+    })
+    .finally(() => console.log("End!"));
+};
+
+getCountryData("vietnam");