nodejs/doc/api/querystring.md

Query String

Stability: 2 - Stable

This module provides utilities for dealing with query strings. It provides the following methods:

querystring.escape

The escape function used by querystring.stringify, provided so that it could be overridden if necessary.

querystring.parse(str[, sep][, eq][, options])

Deserialize a query string to an object. Optionally override the default separator ('&') and assignment ('=') characters.

Options object may contain maxKeys property (equal to 1000 by default), it'll be used to limit processed keys. Set it to 0 to remove key count limitation.

Options object may contain decodeURIComponent property (querystring.unescape by default), it can be used to decode a non-utf8 encoding string if necessary.

Example:

querystring.parse('foo=bar&baz=qux&baz=quux&corge')
// returns { foo: 'bar', baz: ['qux', 'quux'], corge: '' }

// Suppose gbkDecodeURIComponent function already exists,
// it can decode `gbk` encoding string
querystring.parse('w=%D6%D0%CE%C4&foo=bar', null, null,
  { decodeURIComponent: gbkDecodeURIComponent })
// returns { w: '中文', foo: 'bar' }

querystring.stringify(obj[, sep][, eq][, options])

Serialize an object to a query string. Optionally override the default separator ('&') and assignment ('=') characters.

Options object may contain encodeURIComponent property (querystring.escape by default), it can be used to encode string with non-utf8 encoding if necessary.

Example:

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

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

// Suppose gbkEncodeURIComponent function already exists,
// it can encode string with `gbk` encoding
querystring.stringify({ w: '中文', foo: 'bar' }, null, null,
  { encodeURIComponent: gbkEncodeURIComponent })
// returns 'w=%D6%D0%CE%C4&foo=bar'

querystring.unescape

The unescape function used by querystring.parse, provided so that it could be overridden if necessary.

It will try to use decodeURIComponent in the first place, but if that fails it falls back to a safer equivalent that doesn't throw on malformed URLs.