From ce3eba08ded362e874255c8b4bd0290b6aa5a2ca Mon Sep 17 00:00:00 2001
From: Andreas Zweili <andreas@zweili.ch>
Date: Sat, 4 Sep 2021 13:57:56 +0200
Subject: [PATCH] add a watcher

---
 2021-07-30_composition-01-starting-setup/src/App.vue | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/2021-07-30_composition-01-starting-setup/src/App.vue b/2021-07-30_composition-01-starting-setup/src/App.vue
index c6d3d02..09784f0 100644
--- a/2021-07-30_composition-01-starting-setup/src/App.vue
+++ b/2021-07-30_composition-01-starting-setup/src/App.vue
@@ -11,7 +11,7 @@
 </template>
 
 <script>
-import { reactive, computed } from 'vue';
+import { reactive, computed, watch, ref } from 'vue';
 
 export default {
   setup() {
@@ -21,6 +21,16 @@ export default {
       age: 23
     });
 
+    const userAge = ref(23);
+    const userName = ref('Muster');
+
+    watch([userAge, userName], function(newValue, oldValue) {
+      console.log('old age: ', oldValue[0]);
+      console.log('new age: ', newValue[0]);
+      console.log('old name: ', oldValue[1]);
+      console.log('new name: ', newValue[1]);
+    });
+
     user.name = computed(function() {
       return user.firstName + ' ' + user.lastName;
     });