Sync/Async: event loop on browser and runtime node.js

Author: ChauDinh

Sync-Async/Event Loop/index.js

@@ -0,0 +1,43 @@
+// Example 1
+
+// function one(x) {
+//   x++;
+//   setTimeout(() => {
+//     console.log(`setTimeout ${x}`);
+//   });
+//   two(x);
+// }
+
+// function two(y) {
+//   y++;
+//   three(y);
+// }
+
+// function three(z) {
+//   z++;
+//   console.log(`This is the third func: ${z}`);
+// }
+
+// one(1);
+
+// Example 2
+const s = Date.now();
+
+// C: a asynchronous code
+setTimeout(() => {
+  console.log(`setTimeout 1st: ${Date.now() - s}`);
+}, 1000);
+
+// D: another asynchronous code
+setTimeout(() => {
+  console.log(`setTimeout 2nd: ${Date.now() - s}`);
+}, 3000);
+
+// A: a synchronous code takes 3.5s
+let result = 0;
+for (let i = 0; i < 3000000000; i++) {
+  result = result + i;
+}
+
+// B: another synchronous code, will be blocked, and run after A
+console.log(`Sync: ${result} - ${Date.now() - s}`);