Snippet

Watching Reactive Changes

The watch function allows you to perform 'side effects' (like fetching data) whenever a specific piece of data, such as a prop, changes its value.

snippet.js

javascript

import { watch } from 'vue';
 
watch(() => props.userId, (newId) => {
  console.log('User ID changed to:', newId);
});

vue

Breakdown

watch(() => props.userId, ...)

Defines the source to watch; using a function here ensures we track the reactive prop correctly.

(newId) => { ... }

This function runs automatically and receives the updated value as its first argument.