last-endcode
diff --git a/‎17.addEventListener.js
+12 b/‎17.addEventListener.js
+12
@@ -0,0 +1,12 @@
+// select element
+// addEventListener
+// what event,
+// and what to do (callback function/annonymous funciton/function reference)
+
+const btn = document.querySelector('.btn');
+const h3 = document.querySelector('h3');
+
+btn.addEventListener('click', function () {
+  // if click btn h3 will add class blue
+  h3.classList.add('blue');
+});