Query parameters in NestJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to extract query parameters in a NestJS controller method.

NestJS

import { Controller, Get, [1] } from '@nestjs/common';

@Controller('items')
export class ItemsController {
  @Get()
  findAll(@[1]() query: any) {
    return query;
  }
}

Drag options to blanks, or click blank then click option'

AQuery

BBody

CParam

DHeaders

Attempts:

3 left

💡 Hint

Common Mistakes

Using @Body() instead of @Query() to get query parameters.

Using @Param() which extracts route parameters, not query parameters.

The @Query() decorator extracts query parameters from the URL in NestJS.

2fill in blank

medium

Complete the code to type the query parameter object in a NestJS controller.

NestJS

import { Controller, Get, Query } from '@nestjs/common';

@Controller('search')
export class SearchController {
  @Get()
  search(@Query() query: [1]) {
    return query;
  }
}

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Anumber

Bstring

Cany

Dboolean

Attempts:

3 left

💡 Hint

Common Mistakes

Using string which only allows a single string, not an object.

Using number or boolean which are too restrictive.

Query parameters can be any shape, so any is often used for flexibility.

3fill in blank

hard

Fix the error in the code to correctly extract a specific query parameter named 'page'.

NestJS

import { Controller, Get, Query } from '@nestjs/common';

@Controller('posts')
export class PostsController {
  @Get()
  getPosts(@Query('[1]') page: string) {
    return `Page number is ${page}`;
  }
}

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Apage

BPage

Cpages

Dnumber

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect casing like 'Page' instead of 'page'.

Using plural or different names like 'pages' or 'number'.

The string inside @Query() must exactly match the query parameter name, which is 'page'.

4fill in blank

hard

Fill both blanks to destructure 'limit' and 'offset' query parameters with default values.

NestJS

import { Controller, Get, Query } from '@nestjs/common';

@Controller('data')
export class DataController {
  @Get()
  fetchData(@Query() { [1] = 10, [2] = 0 }: any) {
    return { limit: [1], offset: [2] };
  }
}

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Alimit

Boffset

Cpage

Dsize

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong parameter names like 'page' or 'size'.

Not providing default values causing undefined errors.

Destructuring the query object with default values for limit and offset allows setting defaults if parameters are missing.

5fill in blank

hard

Fill all three blanks to validate and transform a query parameter 'count' to a number using a pipe.

NestJS

import { Controller, Get, Query, [1] } from '@nestjs/common';

@Controller('stats')
export class StatsController {
  @Get()
  getStats(@Query('[2]', new [3]()) count: number) {
    return `Count is ${count}`;
  }
}

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AParseIntPipe

Bcount

CValidationPipe

DParseBoolPipe

Attempts:

3 left

💡 Hint

Common Mistakes

Using ValidationPipe which does not convert types automatically.

Using ParseBoolPipe which is for boolean values.

Mismatching parameter name.

The ParseIntPipe converts the 'count' query parameter from string to number and validates it.