In Vue 3, there are three ways to monitor nested properties using the watch function: 1. Use the getter function to accurately monitor specific nested paths, such as watch(() => someObject.nested.property, callback); 2. Add the { deep: true } option to deeply monitor changes within the entire object, which is suitable for situations where the structure is complex and does not care about which property changes; 3. Return an array in getter to listen to multiple nested values ??at the same time, which can be used in combination with deep: true; in addition, if ref is used, the nested properties in its .value need to be tracked through getter.
Sure, here's a practical guide to watching nested properties in Vue 3 using the watch function:
In Vue 3, when you want to watch deeply nested reactive data — like an object inside another object — there are a few key things to know. The built-in watch function can handle it, but how you set it up matters.
Here's how to do it right.
Use a Getter Function for Deep Watching
When dealing with nested properties, the simplest and most reliable way is to use a getter function inside your watch . This tells Vue exactly which part of your data to observe.
For example:
watch(
() => someObject.nested.property,
(newVal) => {
console.log('Nested property changed:', newVal);
}
);This works because Vue tracks what you access inside the getter. Even if the structure is deep, as long as you reference it directly in the getter, Vue will react when it changes.
?? Just remember: this only watches changes to the reference . If you're modifying a value inside a complex object (like an array element or nested object field), you need deeper tracking.
Add { deep: true } When Watching the Whole Object
If you want to detect any change within a nested object — not just when the whole property is replaced — add the deep: true option.
watch(
() => someObject,
(newVal, oldVal) => {
console.log('Something inside the object changed');
},
{ deep: true }
);This tells Vue to recursively check for changes across all nested values.
Use cases where this helps:
- You're editing a form object that has multiple levels.
- You're working with arrays of objects and mutating them in place.
- You don't care which part changed, just that something inside the structure did.
Just be aware: deep watching can be less efficient than watching specific keys, especially on large objects.
Watch Multiple Nested Values ??at Once
Sometimes you need to track more than one nested path. In that case, return an array from your watcher's getter:
watch(
() => [
someObject.nested.property,
AnotherObject.level.deep.value
],
([newProp, newValue], [oldProp, oldValue]) => {
// Both values ??are available here
}
);This way, Vue will trigger your callback whenever either of those paths changes.
You can also combine this with deep: true if needed.
Reactive vs Refs: A Small Gotcha
If you're using ref s instead of reactive , you don't need to wrap them in a getter unless you're accessing a nested property. For example:
const myRef = ref({ foo: { bar: 'baz' } });
watch(
() => myRef.value.foo.bar,
(newVal) => {
console.log('Bar changed:', newVal);
}
); Because myRef.value is an object, accessing .foo.bar requires a getter to properly track dependencies.
But if you were watching the entire myRef.value , you could skip the getter and still use deep: true .
So yes, watching nested properties in Vue 3 is totally possible — just make sure to either:
- Use a getter to target the exact path,
- Or enable
deep: trueif you want full traversal.
It's not hard once you get used to how the reactivity system tracks dependencies.
Basically that's it.
The above is the detailed content of How to watch nested properties in Vue 3?. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
What is headless UI in Vue?
Jul 08, 2025 am 01:38 AM
HeadlessUIinVue refers to a library of UI components that provide no preset styles and only contains core logic and behavior. Its features include: 1. No style restrictions, developers can customize the design; 2. Focus on barrier-free and interactive logic, such as keyboard navigation, state management, etc.; 3. Support Vue framework integration, exposing the control interface through combinable functions or components. Reasons for use include: maintaining design consistency, built-in accessibility, strong component reusability, and lightweight library size. In practical applications, developers need to write HTML and CSS themselves. For example, when building a drop-down menu, the library handles state and interaction, while developers decide on visual presentation. Mainstream libraries include HeadlessUI and RadixVue for TailwindLabs, suitable for
How to watch nested properties in Vue 3?
Jul 07, 2025 am 12:51 AM
In Vue3, there are three ways to monitor nested properties using the watch function: 1. Use the getter function to accurately monitor specific nested paths, such as watch(()=>someObject.nested.property,callback); 2. Add the {deep:true} option to deeply monitor changes within the entire object, which is suitable for situations where the structure is complex and does not care about which property changes; 3. Return an array in the getter to listen to multiple nested values ??at the same time, which can be used in combination with deep:true; in addition, if ref is used, the nested properties in its .value need to be tracked through getter.
How to build a component library with Vue?
Jul 10, 2025 pm 12:14 PM
Building a Vue component library requires designing the structure around the business scenario and following the complete process of development, testing and release. 1. The structural design should be classified according to functional modules, including basic components, layout components and business components; 2. Use SCSS or CSS variables to unify the theme and style; 3. Unify the naming specifications and introduce ESLint and Prettier to ensure the consistent code style; 4. Display the usage of components on the supporting document site; 5. Use Vite and other tools to package as NPM packages and configure rollupOptions; 6. Follow the semver specification to manage versions and changelogs when publishing.
Key differences between Vue 2 and Vue 3?
Jul 09, 2025 am 01:29 AM
Vue3 has improved in many key aspects compared to Vue2. 1.Composition API provides a more flexible logical organization method, allowing centralized management of related logic, while still supporting Vue2's Options API; 2. Better performance and smaller package size, the core library is reduced by about 30%, the rendering speed is faster and supports better tree shake optimization; 3. The responsive system uses ES6Proxy to solve the problem of unable to automatically track attribute addition and deletion in Vue2, making the responsive mechanism more natural and consistent; 4. Built-in better support for TypeScript, support multiple node fragments and custom renderer API, improving flexibility and future adaptability. Overall, Vue3 is a smooth upgrade to Vue2,
How to create a Vue 3 project with Vite?
Jul 05, 2025 am 01:39 AM
It is recommended to use Vite to create Vue3 projects because it uses the browser's native ES module support and has a fast startup speed in development mode. 1. Make sure to install Node.js (16.x or higher) and npm/yarn/pnpm; 2. Run npmcreatevite@latestmy-vue-app--templatevue initialization project; 3. Follow the prompts to select TypeScript, VueRouter and other configurations; 4. Execute cdmy-vue-app and npminstall installation dependencies; 5. Use npmrundev to start the development server. Optional configurations include automatic browser opening, proxy settings, alias paths, and packaging optimizations. Recommended insurance
How to define routes in vue router?
Jul 05, 2025 am 12:58 AM
Defining routes in Vue projects requires understanding the structure and configuration. The steps are as follows: 1. Install and introduce vue-router, create a routing instance, and pass in a routes array containing path and component; 2. Use dynamic routing matching such as /user/:id to obtain parameters; 3. Use children attribute to implement nested routes; 4. Name the routes with the name attribute for jumping; 5. Use redirect for path redirect. After mastering these core points, you can configure routing efficiently.
Benefits of using ?
Jul 08, 2025 am 12:20 AM
? in regular expressions are used to convert greedy matches to non-greedy, achieving more accurate matches. 1. It makes the content as little as possible to match as little as possible to avoid mismatch across tags or fields; 2. It is often used in scenarios such as HTML parsing, log analysis, URL extraction, etc. that require precise control of the scope; 3. When using it, it is necessary to note that not all quantifiers are applicable. Some tools need to manually enable non-greedy mode, and complex structures need to be combined with grouping and assertions to ensure accuracy. Mastering this technique can significantly improve text processing efficiency.
What is CORS and how does it affect Vue development?
Jul 07, 2025 am 12:11 AM
CORSissuesinVueoccurduetothebrowser'ssame-originpolicywhenthefrontendandbackenddomainsdiffer.Duringdevelopment,configureaproxyinvue.config.jstoredirectAPIrequeststhroughthedevserver.Inproduction,ensurethebackendsetsproperCORSheaders,allowingspecifico
