Route parameters in NestJS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What are route parameters in NestJS?

Route parameters are dynamic parts of a URL that can change. They let you capture values from the URL to use in your code, like an ID or a name.

beginner

How do you define a route parameter in a NestJS controller?

You add a colon before the parameter name in the route path, like @Get(':id'). This tells NestJS to expect a dynamic value in that spot.

beginner

How do you access route parameters inside a NestJS controller method?

Use the @Param() decorator to get the parameter value. For example, @Param('id') gets the value of the 'id' parameter from the URL.

intermediate

What happens if you define multiple route parameters in NestJS?

You can define many parameters like @Get(':userId/orders/:orderId'). Each parameter can be accessed separately using @Param('userId') and @Param('orderId').

beginner

Why are route parameters useful in web applications?

They let your app respond to different URLs with different data. For example, showing details for a specific user or product by using their ID in the URL.

How do you declare a route parameter named 'id' in a NestJS controller?

A @Get(':id')

B @Get('id')

C @Get('{id}')

D @Get('/id')

Route parameters use a colon before the name, so ':id' is correct.

Which decorator do you use to access a route parameter inside a NestJS method?

A @Param()

B @Headers()

C @Query()

D @Body()

@Param() extracts route parameters from the URL.

What will @Param('userId') return if the route is '/users/42' and the route is defined as @Get('users/:userId')?

A :userId

B users

C 42

D undefined

The value '42' is captured as the userId parameter.

Can you have more than one route parameter in a single route in NestJS?

A No, only one parameter is allowed

B Yes, multiple parameters separated by slashes

C Yes, but only if they have the same name

D No, parameters must be in the query string

You can define multiple parameters like ':userId/orders/:orderId'.

What is the main benefit of using route parameters?

A To style the URL

B To secure the route

C To cache the response

D To capture dynamic values from the URL for processing

Route parameters let you get dynamic values from the URL to use in your app.

Explain how to define and access a route parameter in a NestJS controller.

Think about how URLs can have parts that change, like user IDs.

Describe a real-life example where route parameters are useful in a web app.

Imagine clicking on a link to see a specific item or profile.