querystring

The node:querystring module provides utilities for parsing and formatting URL query strings. It can be accessed using:

import querystring from 'node:querystring';

querystring is more performant than URLSearchParams but is not a standardized API. Use URLSearchParams when performance is not critical or when compatibility with browser code is desirable.

Usage in Deno

import * as mod from "node:querystring";

function escape

Usage in Deno

import { escape } from "node:querystring";

escape(str: string): string

The querystring.escape() method performs URL percent-encoding on the given str in a manner that is optimized for the specific requirements of URL query strings.

The querystring.escape() method is used by querystring.stringify() and is generally not expected to be used directly. It is exported primarily to allow application code to provide a replacement percent-encoding implementation if necessary by assigning querystring.escape to an alternative function.

Parameters

str: string

Return Type

string

function parse

Usage in Deno

import { parse } from "node:querystring";

parse(

str: string,

sep?: string,

eq?: string,

options?: ParseOptions,
): ParsedUrlQuery

The querystring.parse() method parses a URL query string (str) into a collection of key and value pairs.

For example, the query string 'foo=bar&abc=xyz&abc=123' is parsed into:

{
  "foo": "bar",
  "abc": ["xyz", "123"]
}

The object returned by the querystring.parse() method does not prototypically inherit from the JavaScript Object. This means that typical Object methods such as obj.toString(), obj.hasOwnProperty(), and others are not defined and will not work.

By default, percent-encoded characters within the query string will be assumed to use UTF-8 encoding. If an alternative character encoding is used, then an alternative decodeURIComponent option will need to be specified:

// Assuming gbkDecodeURIComponent function already exists...

querystring.parse('w=%D6%D0%CE%C4&#x26;foo=bar', null, null,
                  { decodeURIComponent: gbkDecodeURIComponent });

Parameters

str: string

The URL query string to parse

sep: string = '&'

optional

The substring used to delimit key and value pairs in the query string.

eq: string = '='

optional

The substring used to delimit keys and values in the query string.

options: ParseOptions

optional

Return Type

ParsedUrlQuery

function stringify

Usage in Deno

import { stringify } from "node:querystring";

stringify(

obj?: ParsedUrlQueryInput,

sep?: string,

eq?: string,

options?: StringifyOptions,
): string

The querystring.stringify() method produces a URL query string from a given obj by iterating through the object's "own properties".

querystring.stringify({ foo: 'bar', baz: ['qux', 'quux'], corge: '' });
// Returns 'foo=bar&#x26;baz=qux&#x26;baz=quux&#x26;corge='

querystring.stringify({ foo: 'bar', baz: 'qux' }, ';', ':');
// Returns 'foo:bar;baz:qux'

By default, characters requiring percent-encoding within the query string will be encoded as UTF-8. If an alternative encoding is required, then an alternative encodeURIComponent option will need to be specified:

// Assuming gbkEncodeURIComponent function already exists,

querystring.stringify({ w: '中文', foo: 'bar' }, null, null,
                      { encodeURIComponent: gbkEncodeURIComponent });

Parameters

obj: ParsedUrlQueryInput

optional

The object to serialize into a URL query string

sep: string = '&'

optional

The substring used to delimit key and value pairs in the query string.

eq: string = '='

optional

. The substring used to delimit keys and values in the query string.

options: StringifyOptions

optional

Return Type

string

function unescape

Usage in Deno

import { unescape } from "node:querystring";

unescape(str: string): string

The querystring.unescape() method performs decoding of URL percent-encoded characters on the given str.

The querystring.unescape() method is used by querystring.parse() and is generally not expected to be used directly. It is exported primarily to allow application code to provide a replacement decoding implementation if necessary by assigning querystring.unescape to an alternative function.

By default, the querystring.unescape() method will attempt to use the JavaScript built-in decodeURIComponent() method to decode. If that fails, a safer equivalent that does not throw on malformed URLs will be used.

Parameters

str: string

Return Type

string

interface ParsedUrlQuery

extends [NodeJS.Dict]<string | string[]>

Usage in Deno

import { type ParsedUrlQuery } from "node:querystring";

interface ParsedUrlQueryInput

extends [NodeJS.Dict]<

Usage in Deno

import { type ParsedUrlQueryInput } from "node:querystring";

interface ParseOptions

Usage in Deno

import { type ParseOptions } from "node:querystring";

Properties

maxKeys: number | undefined

optional

Specifies the maximum number of keys to parse. Specify 0 to remove key counting limitations.

decodeURIComponent: ((str: string) => string) | undefined

optional

The function to use when decoding percent-encoded characters in the query string.

interface StringifyOptions

Usage in Deno

import { type StringifyOptions } from "node:querystring";

The node:querystring module provides utilities for parsing and formatting URL query strings. It can be accessed using:

import querystring from 'node:querystring';

querystring is more performant than URLSearchParams but is not a standardized API. Use URLSearchParams when performance is not critical or when compatibility with browser code is desirable.

Properties

encodeURIComponent: ((str: string) => string) | undefined

optional

The function to use when converting URL-unsafe characters to percent-encoding in the query string.

See

source

variable decode

Usage in Deno

import { decode } from "node:querystring";

The querystring.decode() function is an alias for querystring.parse().

Type

parse

variable encode

Usage in Deno

import { encode } from "node:querystring";

The querystring.encode() function is an alias for querystring.stringify().

Type

stringify