doc: add examples for implementing ESM

Fixes: https://github.com/nodejs/node/issues/28060

PR-URL: https://github.com/nodejs/node/pull/33168
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Bradley Farias <bradley.meck@gmail.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/doc/api/esm.md b/doc/api/esm.md
index 30534a5cda..f3a34e7d46 100644
--- a/doc/api/esm.md
+++ b/doc/api/esm.md
@@ -13,6 +13,27 @@ ECMAScript modules are [the official standard format][] to package JavaScript
 code for reuse. Modules are defined using a variety of [`import`][] and
 [`export`][] statements.
 
+The following example of an ES module exports a function:
+
+```js
+// addTwo.js
+function addTwo(num) {
+  return num + 2;
+}
+
+export { addTwo };
+```
+
+The following example of an ES module imports the function from `addTwo.js`:
+
+```js
+// app.js
+import { addTwo } from './addTwo.js';
+
+// Prints: 6
+console.log(addTwo(4));
+```
+
 Node.js fully supports ECMAScript modules as they are currently specified and
 provides limited interoperability between them and the existing module format,
 [CommonJS][].