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5ed493e548 docs: update useParams examples and pages usage (#61595)
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Updated https://nextjs.org/docs/app/api-reference/functions/use-params
with:
* returns block, examples table: route with no dynamic parameters should
return an empty object
* returns block, `pages` usage: if `useParams` is used in `pages` it
will return `null` only for the initial render and will update its value
with dynamic parameters following the same rules as stated in the doc
above this point.

---------

Co-authored-by: Sam Ko <[email protected]>
2024-02-04 23:44:43 +00:00

74 lines
2.5 KiB
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---
title: useParams
description: API Reference for the useParams hook.
---
`useParams` is a **Client Component** hook that lets you read a route's [dynamic params](/docs/app/building-your-application/routing/dynamic-routes) filled in by the current URL.
```tsx filename="app/example-client-component.tsx" switcher
'use client'
import { useParams } from 'next/navigation'
export default function ExampleClientComponent() {
const params = useParams<{ tag: string; item: string }>()
// Route -> /shop/[tag]/[item]
// URL -> /shop/shoes/nike-air-max-97
// `params` -> { tag: 'shoes', item: 'nike-air-max-97' }
console.log(params)
return <></>
}
```
```jsx filename="app/example-client-component.js" switcher
'use client'
import { useParams } from 'next/navigation'
export default function ExampleClientComponent() {
const params = useParams()
// Route -> /shop/[tag]/[item]
// URL -> /shop/shoes/nike-air-max-97
// `params` -> { tag: 'shoes', item: 'nike-air-max-97' }
console.log(params)
return <></>
}
```
## Parameters
```tsx
const params = useParams()
```
`useParams` does not take any parameters.
## Returns
`useParams` returns an object containing the current route's filled in [dynamic parameters](/docs/app/building-your-application/routing/dynamic-routes).
- Each property in the object is an active dynamic segment.
- The properties name is the segment's name, and the properties value is what the segment is filled in with.
- The properties value will either be a `string` or array of `string`'s depending on the [type of dynamic segment](/docs/app/building-your-application/routing/dynamic-routes).
- If the route contains no dynamic parameters, `useParams` returns an empty object.
- If used in Pages Router, `useParams` will return `null` on the initial render and updates with properties following the rules above once the router is ready.
For example:
| Route | URL | `useParams()` |
| ------------------------------- | ----------- | ------------------------- |
| `app/shop/page.js` | `/shop` | `{}` |
| `app/shop/[slug]/page.js` | `/shop/1` | `{ slug: '1' }` |
| `app/shop/[tag]/[item]/page.js` | `/shop/1/2` | `{ tag: '1', item: '2' }` |
| `app/shop/[...slug]/page.js` | `/shop/1/2` | `{ slug: ['1', '2'] }` |
## Version History
| Version | Changes |
| --------- | ----------------------- |
| `v13.3.0` | `useParams` introduced. |