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Node.js v8.9.2 Documentation
Table of Contents
- URL
- URL Strings and URL Objects
- The WHATWG URL API
- Class: URL
- Class: URLSearchParams
- Constructor: new URLSearchParams()
- Constructor: new URLSearchParams(string)
- Constructor: new URLSearchParams(obj)
- Constructor: new URLSearchParams(iterable)
- urlSearchParams.append(name, value)
- urlSearchParams.delete(name)
- urlSearchParams.entries()
- urlSearchParams.forEach(fn[, thisArg])
- urlSearchParams.get(name)
- urlSearchParams.getAll(name)
- urlSearchParams.has(name)
- urlSearchParams.keys()
- urlSearchParams.set(name, value)
- urlSearchParams.sort()
- urlSearchParams.toString()
- urlSearchParams.values()
- urlSearchParams[@@iterator]()
- url.domainToASCII(domain)
- url.domainToUnicode(domain)
- url.format(URL[, options])
- Legacy URL API
- Percent-Encoding in URLs
URL#
The url
module provides utilities for URL resolution and parsing. It can be
accessed using:
const url = require('url');
URL Strings and URL Objects#
A URL string is a structured string containing multiple meaningful components. When parsed, a URL object is returned containing properties for each of these components.
The url
module provides two APIs for working with URLs: a legacy API that is
Node.js specific, and a newer API that implements the same
WHATWG URL Standard used by web browsers.
Note: While the Legacy API has not been deprecated, it is maintained solely for backwards compatibility with existing applications. New application code should use the WHATWG API.
A comparison between the WHATWG and Legacy APIs is provided below. Above the URL
'http://user:pass@sub.host.com:8080/p/a/t/h?query=string#hash'
, properties of
an object returned by the legacy url.parse()
are shown. Below it are
properties of a WHATWG URL
object.
Note: WHATWG URL's origin
property includes protocol
and host
, but not
username
or password
.
┌─────────────────────────────────────────────────────────────────────────────────────────────┐
│ href │
├──────────┬──┬─────────────────────┬─────────────────────┬───────────────────────────┬───────┤
│ protocol │ │ auth │ host │ path │ hash │
│ │ │ ├──────────────┬──────┼──────────┬────────────────┤ │
│ │ │ │ hostname │ port │ pathname │ search │ │
│ │ │ │ │ │ ├─┬──────────────┤ │
│ │ │ │ │ │ │ │ query │ │
" https: // user : pass @ sub.host.com : 8080 /p/a/t/h ? query=string #hash "
│ │ │ │ │ hostname │ port │ │ │ │
│ │ │ │ ├──────────────┴──────┤ │ │ │
│ protocol │ │ username │ password │ host │ │ │ │
├──────────┴──┼──────────┴──────────┼─────────────────────┤ │ │ │
│ origin │ │ origin │ pathname │ search │ hash │
├─────────────┴─────────────────────┴─────────────────────┴──────────┴────────────────┴───────┤
│ href │
└─────────────────────────────────────────────────────────────────────────────────────────────┘
(all spaces in the "" line should be ignored -- they are purely for formatting)
Parsing the URL string using the WHATWG API:
const { URL } = require('url');
const myURL =
new URL('https://user:pass@sub.host.com:8080/p/a/t/h?query=string#hash');
Note: In Web Browsers, the WHATWG URL
class is a global that is always
available. In Node.js, however, the URL
class must be accessed via
require('url').URL
.
Parsing the URL string using the Legacy API:
const url = require('url');
const myURL =
url.parse('https://user:pass@sub.host.com:8080/p/a/t/h?query=string#hash');
The WHATWG URL API#
Class: URL#
Browser-compatible URL
class, implemented by following the WHATWG URL
Standard. Examples of parsed URLs may be found in the Standard itself.
Note: In accordance with browser conventions, all properties of URL
objects
are implemented as getters and setters on the class prototype, rather than as
data properties on the object itself. Thus, unlike legacy urlObjects, using
the delete
keyword on any properties of URL
objects (e.g. delete
myURL.protocol
, delete myURL.pathname
, etc) has no effect but will still
return true
.
Constructor: new URL(input[, base])#
Creates a new URL
object by parsing the input
relative to the base
. If
base
is passed as a string, it will be parsed equivalent to new URL(base)
.
const { URL } = require('url');
const myURL = new URL('/foo', 'https://example.org/');
// https://example.org/foo
A TypeError
will be thrown if the input
or base
are not valid URLs. Note
that an effort will be made to coerce the given values into strings. For
instance:
const { URL } = require('url');
const myURL = new URL({ toString: () => 'https://example.org/' });
// https://example.org/
Unicode characters appearing within the hostname of input
will be
automatically converted to ASCII using the Punycode algorithm.
const { URL } = require('url');
const myURL = new URL('https://你好你好');
// https://xn--6qqa088eba/
Note: This feature is only available if the node
executable was compiled
with ICU enabled. If not, the domain names are passed through unchanged.
url.hash#
Gets and sets the fragment portion of the URL.
const { URL } = require('url');
const myURL = new URL('https://example.org/foo#bar');
console.log(myURL.hash);
// Prints #bar
myURL.hash = 'baz';
console.log(myURL.href);
// Prints https://example.org/foo#baz
Invalid URL characters included in the value assigned to the hash
property
are percent-encoded. Note that the selection of which characters to
percent-encode may vary somewhat from what the url.parse()
and
url.format()
methods would produce.
url.host#
Gets and sets the host portion of the URL.
const { URL } = require('url');
const myURL = new URL('https://example.org:81/foo');
console.log(myURL.host);
// Prints example.org:81
myURL.host = 'example.com:82';
console.log(myURL.href);
// Prints https://example.com:82/foo
Invalid host values assigned to the host
property are ignored.
url.hostname#
Gets and sets the hostname portion of the URL. The key difference between
url.host
and url.hostname
is that url.hostname
does not include the
port.
const { URL } = require('url');
const myURL = new URL('https://example.org:81/foo');
console.log(myURL.hostname);
// Prints example.org
myURL.hostname = 'example.com:82';
console.log(myURL.href);
// Prints https://example.com:81/foo
Invalid hostname values assigned to the hostname
property are ignored.
url.href#
Gets and sets the serialized URL.
const { URL } = require('url');
const myURL = new URL('https://example.org/foo');
console.log(myURL.href);
// Prints https://example.org/foo
myURL.href = 'https://example.com/bar';
console.log(myURL.href);
// Prints https://example.com/bar
Getting the value of the href
property is equivalent to calling
url.toString()
.
Setting the value of this property to a new value is equivalent to creating a
new URL
object using new URL(value)
. Each of the URL
object's properties will be modified.
If the value assigned to the href
property is not a valid URL, a TypeError
will be thrown.
url.origin#
Gets the read-only serialization of the URL's origin.
const { URL } = require('url');
const myURL = new URL('https://example.org/foo/bar?baz');
console.log(myURL.origin);
// Prints https://example.org
const { URL } = require('url');
const idnURL = new URL('https://你好你好');
console.log(idnURL.origin);
// Prints https://xn--6qqa088eba
console.log(idnURL.hostname);
// Prints xn--6qqa088eba
url.password#
Gets and sets the password portion of the URL.
const { URL } = require('url');
const myURL = new URL('https://abc:xyz@example.com');
console.log(myURL.password);
// Prints xyz
myURL.password = '123';
console.log(myURL.href);
// Prints https://abc:123@example.com
Invalid URL characters included in the value assigned to the password
property
are percent-encoded. Note that the selection of which characters to
percent-encode may vary somewhat from what the url.parse()
and
url.format()
methods would produce.
url.pathname#
Gets and sets the path portion of the URL.
const { URL } = require('url');
const myURL = new URL('https://example.org/abc/xyz?123');
console.log(myURL.pathname);
// Prints /abc/xyz
myURL.pathname = '/abcdef';
console.log(myURL.href);
// Prints https://example.org/abcdef?123
Invalid URL characters included in the value assigned to the pathname
property are percent-encoded. Note that the selection of which characters
to percent-encode may vary somewhat from what the url.parse()
and
url.format()
methods would produce.
url.port#
Gets and sets the port portion of the URL.
const { URL } = require('url');
const myURL = new URL('https://example.org:8888');
console.log(myURL.port);
// Prints 8888
// Default ports are automatically transformed to the empty string
// (HTTPS protocol's default port is 443)
myURL.port = '443';
console.log(myURL.port);
// Prints the empty string
console.log(myURL.href);
// Prints https://example.org/
myURL.port = 1234;
console.log(myURL.port);
// Prints 1234
console.log(myURL.href);
// Prints https://example.org:1234/
// Completely invalid port strings are ignored
myURL.port = 'abcd';
console.log(myURL.port);
// Prints 1234
// Leading numbers are treated as a port number
myURL.port = '5678abcd';
console.log(myURL.port);
// Prints 5678
// Non-integers are truncated
myURL.port = 1234.5678;
console.log(myURL.port);
// Prints 1234
// Out-of-range numbers are ignored
myURL.port = 1e10;
console.log(myURL.port);
// Prints 1234
The port value may be set as either a number or as a String containing a number
in the range 0
to 65535
(inclusive). Setting the value to the default port
of the URL
objects given protocol
will result in the port
value becoming
the empty string (''
).
If an invalid string is assigned to the port
property, but it begins with a
number, the leading number is assigned to port
. Otherwise, or if the number
lies outside the range denoted above, it is ignored.
url.protocol#
Gets and sets the protocol portion of the URL.
const { URL } = require('url');
const myURL = new URL('https://example.org');
console.log(myURL.protocol);
// Prints https:
myURL.protocol = 'ftp';
console.log(myURL.href);
// Prints ftp://example.org/
Invalid URL protocol values assigned to the protocol
property are ignored.
url.search#
Gets and sets the serialized query portion of the URL.
const { URL } = require('url');
const myURL = new URL('https://example.org/abc?123');
console.log(myURL.search);
// Prints ?123
myURL.search = 'abc=xyz';
console.log(myURL.href);
// Prints https://example.org/abc?abc=xyz
Any invalid URL characters appearing in the value assigned the search
property will be percent-encoded. Note that the selection of which
characters to percent-encode may vary somewhat from what the url.parse()
and url.format()
methods would produce.
url.searchParams#
Gets the URLSearchParams
object representing the query parameters of the
URL. This property is read-only; to replace the entirety of query parameters of
the URL, use the url.search
setter. See URLSearchParams
documentation for details.
url.username#
Gets and sets the username portion of the URL.
const { URL } = require('url');
const myURL = new URL('https://abc:xyz@example.com');
console.log(myURL.username);
// Prints abc
myURL.username = '123';
console.log(myURL.href);
// Prints https://123:xyz@example.com/
Any invalid URL characters appearing in the value assigned the username
property will be percent-encoded. Note that the selection of which
characters to percent-encode may vary somewhat from what the url.parse()
and url.format()
methods would produce.
url.toString()#
- Returns: <string>
The toString()
method on the URL
object returns the serialized URL. The
value returned is equivalent to that of url.href
and url.toJSON()
.
Because of the need for standard compliance, this method does not allow users
to customize the serialization process of the URL. For more flexibility,
require('url').format()
method might be of interest.
url.toJSON()#
- Returns: <string>
The toJSON()
method on the URL
object returns the serialized URL. The
value returned is equivalent to that of url.href
and
url.toString()
.
This method is automatically called when an URL
object is serialized
with JSON.stringify()
.
const { URL } = require('url');
const myURLs = [
new URL('https://www.example.com'),
new URL('https://test.example.org')
];
console.log(JSON.stringify(myURLs));
// Prints ["https://www.example.com/","https://test.example.org/"]
Class: URLSearchParams#
The URLSearchParams
API provides read and write access to the query of a
URL
. The URLSearchParams
class can also be used standalone with one of the
four following constructors.
The WHATWG URLSearchParams
interface and the querystring
module have
similar purpose, but the purpose of the querystring
module is more
general, as it allows the customization of delimiter characters (&
and =
).
On the other hand, this API is designed purely for URL query strings.
const { URL, URLSearchParams } = require('url');
const myURL = new URL('https://example.org/?abc=123');
console.log(myURL.searchParams.get('abc'));
// Prints 123
myURL.searchParams.append('abc', 'xyz');
console.log(myURL.href);
// Prints https://example.org/?abc=123&abc=xyz
myURL.searchParams.delete('abc');
myURL.searchParams.set('a', 'b');
console.log(myURL.href);
// Prints https://example.org/?a=b
const newSearchParams = new URLSearchParams(myURL.searchParams);
// The above is equivalent to
// const newSearchParams = new URLSearchParams(myURL.search);
newSearchParams.append('a', 'c');
console.log(myURL.href);
// Prints https://example.org/?a=b
console.log(newSearchParams.toString());
// Prints a=b&a=c
// newSearchParams.toString() is implicitly called
myURL.search = newSearchParams;
console.log(myURL.href);
// Prints https://example.org/?a=b&a=c
newSearchParams.delete('a');
console.log(myURL.href);
// Prints https://example.org/?a=b&a=c
Constructor: new URLSearchParams()#
Instantiate a new empty URLSearchParams
object.
Constructor: new URLSearchParams(string)#
string
<string> A query string
Parse the string
as a query string, and use it to instantiate a new
URLSearchParams
object. A leading '?'
, if present, is ignored.
const { URLSearchParams } = require('url');
let params;
params = new URLSearchParams('user=abc&query=xyz');
console.log(params.get('user'));
// Prints 'abc'
console.log(params.toString());
// Prints 'user=abc&query=xyz'
params = new URLSearchParams('?user=abc&query=xyz');
console.log(params.toString());
// Prints 'user=abc&query=xyz'
Constructor: new URLSearchParams(obj)#
obj
<Object> An object representing a collection of key-value pairs
Instantiate a new URLSearchParams
object with a query hash map. The key and
value of each property of obj
are always coerced to strings.
Note: Unlike querystring
module, duplicate keys in the form of array
values are not allowed. Arrays are stringified using array.toString()
,
which simply joins all array elements with commas.
const { URLSearchParams } = require('url');
const params = new URLSearchParams({
user: 'abc',
query: ['first', 'second']
});
console.log(params.getAll('query'));
// Prints [ 'first,second' ]
console.log(params.toString());
// Prints 'user=abc&query=first%2Csecond'
Constructor: new URLSearchParams(iterable)#
iterable
<Iterable> An iterable object whose elements are key-value pairs
Instantiate a new URLSearchParams
object with an iterable map in a way that
is similar to Map
's constructor. iterable
can be an Array or any
iterable object. That means iterable
can be another URLSearchParams
, in
which case the constructor will simply create a clone of the provided
URLSearchParams
. Elements of iterable
are key-value pairs, and can
themselves be any iterable object.
Duplicate keys are allowed.
const { URLSearchParams } = require('url');
let params;
// Using an array
params = new URLSearchParams([
['user', 'abc'],
['query', 'first'],
['query', 'second']
]);
console.log(params.toString());
// Prints 'user=abc&query=first&query=second'
// Using a Map object
const map = new Map();
map.set('user', 'abc');
map.set('query', 'xyz');
params = new URLSearchParams(map);
console.log(params.toString());
// Prints 'user=abc&query=xyz'
// Using a generator function
function* getQueryPairs() {
yield ['user', 'abc'];
yield ['query', 'first'];
yield ['query', 'second'];
}
params = new URLSearchParams(getQueryPairs());
console.log(params.toString());
// Prints 'user=abc&query=first&query=second'
// Each key-value pair must have exactly two elements
new URLSearchParams([
['user', 'abc', 'error']
]);
// Throws TypeError [ERR_INVALID_TUPLE]:
// Each query pair must be an iterable [name, value] tuple
urlSearchParams.append(name, value)#
Append a new name-value pair to the query string.
urlSearchParams.delete(name)#
name
<string>
Remove all name-value pairs whose name is name
.
urlSearchParams.entries()#
- Returns: <Iterator>
Returns an ES6 Iterator over each of the name-value pairs in the query.
Each item of the iterator is a JavaScript Array. The first item of the Array
is the name
, the second item of the Array is the value
.
Alias for urlSearchParams[@@iterator]()
.
urlSearchParams.forEach(fn[, thisArg])#
fn
<Function> Function invoked for each name-value pair in the query.thisArg
<Object> Object to be used asthis
value for whenfn
is called
Iterates over each name-value pair in the query and invokes the given function.
const { URL } = require('url');
const myURL = new URL('https://example.org/?a=b&c=d');
myURL.searchParams.forEach((value, name, searchParams) => {
console.log(name, value, myURL.searchParams === searchParams);
});
// Prints:
// a b true
// c d true
urlSearchParams.get(name)#
Returns the value of the first name-value pair whose name is name
. If there
are no such pairs, null
is returned.
urlSearchParams.getAll(name)#
Returns the values of all name-value pairs whose name is name
. If there are
no such pairs, an empty array is returned.
urlSearchParams.has(name)#
Returns true
if there is at least one name-value pair whose name is name
.
urlSearchParams.keys()#
- Returns: <Iterator>
Returns an ES6 Iterator over the names of each name-value pair.
const { URLSearchParams } = require('url');
const params = new URLSearchParams('foo=bar&foo=baz');
for (const name of params.keys()) {
console.log(name);
}
// Prints:
// foo
// foo
urlSearchParams.set(name, value)#
Sets the value in the URLSearchParams
object associated with name
to
value
. If there are any pre-existing name-value pairs whose names are name
,
set the first such pair's value to value
and remove all others. If not,
append the name-value pair to the query string.
const { URLSearchParams } = require('url');
const params = new URLSearchParams();
params.append('foo', 'bar');
params.append('foo', 'baz');
params.append('abc', 'def');
console.log(params.toString());
// Prints foo=bar&foo=baz&abc=def
params.set('foo', 'def');
params.set('xyz', 'opq');
console.log(params.toString());
// Prints foo=def&abc=def&xyz=opq
urlSearchParams.sort()#
Sort all existing name-value pairs in-place by their names. Sorting is done with a stable sorting algorithm, so relative order between name-value pairs with the same name is preserved.
This method can be used, in particular, to increase cache hits.
const { URLSearchParams } = require('url');
const params = new URLSearchParams('query[]=abc&type=search&query[]=123');
params.sort();
console.log(params.toString());
// Prints query%5B%5D=abc&query%5B%5D=123&type=search
urlSearchParams.toString()#
- Returns: <string>
Returns the search parameters serialized as a string, with characters percent-encoded where necessary.
urlSearchParams.values()#
- Returns: <Iterator>
Returns an ES6 Iterator over the values of each name-value pair.
urlSearchParams[@@iterator]()#
- Returns: <Iterator>
Returns an ES6 Iterator over each of the name-value pairs in the query string.
Each item of the iterator is a JavaScript Array. The first item of the Array
is the name
, the second item of the Array is the value
.
Alias for urlSearchParams.entries()
.
const { URLSearchParams } = require('url');
const params = new URLSearchParams('foo=bar&xyz=baz');
for (const [name, value] of params) {
console.log(name, value);
}
// Prints:
// foo bar
// xyz baz
url.domainToASCII(domain)#
Returns the Punycode ASCII serialization of the domain
. If domain
is an
invalid domain, the empty string is returned.
It performs the inverse operation to url.domainToUnicode()
.
const url = require('url');
console.log(url.domainToASCII('español.com'));
// Prints xn--espaol-zwa.com
console.log(url.domainToASCII('中文.com'));
// Prints xn--fiq228c.com
console.log(url.domainToASCII('xn--iñvalid.com'));
// Prints an empty string
url.domainToUnicode(domain)#
Returns the Unicode serialization of the domain
. If domain
is an invalid
domain, the empty string is returned.
It performs the inverse operation to url.domainToASCII()
.
const url = require('url');
console.log(url.domainToUnicode('xn--espaol-zwa.com'));
// Prints español.com
console.log(url.domainToUnicode('xn--fiq228c.com'));
// Prints 中文.com
console.log(url.domainToUnicode('xn--iñvalid.com'));
// Prints an empty string
url.format(URL[, options])#
URL
<URL> A WHATWG URL objectoptions
<Object>auth
<boolean>true
if the serialized URL string should include the username and password,false
otherwise. Defaults totrue
.fragment
<boolean>true
if the serialized URL string should include the fragment,false
otherwise. Defaults totrue
.search
<boolean>true
if the serialized URL string should include the search query,false
otherwise. Defaults totrue
.unicode
<boolean>true
if Unicode characters appearing in the host component of the URL string should be encoded directly as opposed to being Punycode encoded. Defaults tofalse
.
Returns a customizable serialization of a URL String representation of a WHATWG URL object.
The URL object has both a toString()
method and href
property that return
string serializations of the URL. These are not, however, customizable in
any way. The url.format(URL[, options])
method allows for basic customization
of the output.
For example:
const { URL } = require('url');
const myURL = new URL('https://a:b@你好你好?abc#foo');
console.log(myURL.href);
// Prints https://a:b@xn--6qqa088eba/?abc#foo
console.log(myURL.toString());
// Prints https://a:b@xn--6qqa088eba/?abc#foo
console.log(url.format(myURL, { fragment: false, unicode: true, auth: false }));
// Prints 'https://你好你好/?abc'
Legacy URL API#
Legacy urlObject#
The legacy urlObject (require('url').Url
) is created and returned by the
url.parse()
function.
urlObject.auth#
The auth
property is the username and password portion of the URL, also
referred to as "userinfo". This string subset follows the protocol
and
double slashes (if present) and precedes the host
component, delimited by an
ASCII "at sign" (@
). The format of the string is {username}[:{password}]
,
with the [:{password}]
portion being optional.
For example: 'user:pass'
urlObject.hash#
The hash
property consists of the "fragment" portion of the URL including
the leading ASCII hash (#
) character.
For example: '#hash'
urlObject.host#
The host
property is the full lower-cased host portion of the URL, including
the port
if specified.
For example: 'sub.host.com:8080'
urlObject.hostname#
The hostname
property is the lower-cased host name portion of the host
component without the port
included.
For example: 'sub.host.com'
urlObject.href#
The href
property is the full URL string that was parsed with both the
protocol
and host
components converted to lower-case.
For example: 'http://user:pass@sub.host.com:8080/p/a/t/h?query=string#hash'
urlObject.path#
The path
property is a concatenation of the pathname
and search
components.
For example: '/p/a/t/h?query=string'
No decoding of the path
is performed.
urlObject.pathname#
The pathname
property consists of the entire path section of the URL. This
is everything following the host
(including the port
) and before the start
of the query
or hash
components, delimited by either the ASCII question
mark (?
) or hash (#
) characters.
For example '/p/a/t/h'
No decoding of the path string is performed.
urlObject.port#
The port
property is the numeric port portion of the host
component.
For example: '8080'
urlObject.protocol#
The protocol
property identifies the URL's lower-cased protocol scheme.
For example: 'http:'
urlObject.query#
The query
property is either the query string without the leading ASCII
question mark (?
), or an object returned by the querystring
module's
parse()
method. Whether the query
property is a string or object is
determined by the parseQueryString
argument passed to url.parse()
.
For example: 'query=string'
or {'query': 'string'}
If returned as a string, no decoding of the query string is performed. If returned as an object, both keys and values are decoded.
urlObject.search#
The search
property consists of the entire "query string" portion of the
URL, including the leading ASCII question mark (?
) character.
For example: '?query=string'
No decoding of the query string is performed.
urlObject.slashes#
The slashes
property is a boolean
with a value of true
if two ASCII
forward-slash characters (/
) are required following the colon in the
protocol
.
url.format(urlObject)#
urlObject
<Object> | <string> A URL object (as returned byurl.parse()
or constructed otherwise). If a string, it is converted to an object by passing it tourl.parse()
.
The url.format()
method returns a formatted URL string derived from
urlObject
.
If urlObject
is not an object or a string, url.parse()
will throw a
TypeError
.
The formatting process operates as follows:
- A new empty string
result
is created. - If
urlObject.protocol
is a string, it is appended as-is toresult
. - Otherwise, if
urlObject.protocol
is notundefined
and is not a string, anError
is thrown. - For all string values of
urlObject.protocol
that do not end with an ASCII colon (:
) character, the literal string:
will be appended toresult
. - If either of the following conditions is true, then the literal string
//
will be appended toresult
:urlObject.slashes
property is true;urlObject.protocol
begins withhttp
,https
,ftp
,gopher
, orfile
;
- If the value of the
urlObject.auth
property is truthy, and eitherurlObject.host
orurlObject.hostname
are notundefined
, the value ofurlObject.auth
will be coerced into a string and appended toresult
followed by the literal string@
. - If the
urlObject.host
property isundefined
then:- If the
urlObject.hostname
is a string, it is appended toresult
. - Otherwise, if
urlObject.hostname
is notundefined
and is not a string, anError
is thrown. - If the
urlObject.port
property value is truthy, andurlObject.hostname
is notundefined
:- The literal string
:
is appended toresult
, and - The value of
urlObject.port
is coerced to a string and appended toresult
.
- The literal string
- If the
- Otherwise, if the
urlObject.host
property value is truthy, the value ofurlObject.host
is coerced to a string and appended toresult
. - If the
urlObject.pathname
property is a string that is not an empty string:- If the
urlObject.pathname
does not start with an ASCII forward slash (/
), then the literal string '/' is appended toresult
. - The value of
urlObject.pathname
is appended toresult
.
- If the
- Otherwise, if
urlObject.pathname
is notundefined
and is not a string, anError
is thrown. - If the
urlObject.search
property isundefined
and if theurlObject.query
property is anObject
, the literal string?
is appended toresult
followed by the output of calling thequerystring
module'sstringify()
method passing the value ofurlObject.query
. - Otherwise, if
urlObject.search
is a string:- If the value of
urlObject.search
does not start with the ASCII question mark (?
) character, the literal string?
is appended toresult
. - The value of
urlObject.search
is appended toresult
.
- If the value of
- Otherwise, if
urlObject.search
is notundefined
and is not a string, anError
is thrown. - If the
urlObject.hash
property is a string:- If the value of
urlObject.hash
does not start with the ASCII hash (#
) character, the literal string#
is appended toresult
. - The value of
urlObject.hash
is appended toresult
.
- If the value of
- Otherwise, if the
urlObject.hash
property is notundefined
and is not a string, anError
is thrown. result
is returned.
url.parse(urlString[, parseQueryString[, slashesDenoteHost]])#
urlString
<string> The URL string to parse.parseQueryString
<boolean> Iftrue
, thequery
property will always be set to an object returned by thequerystring
module'sparse()
method. Iffalse
, thequery
property on the returned URL object will be an unparsed, undecoded string. Defaults tofalse
.slashesDenoteHost
<boolean> Iftrue
, the first token after the literal string//
and preceding the next/
will be interpreted as thehost
. For instance, given//foo/bar
, the result would be{host: 'foo', pathname: '/bar'}
rather than{pathname: '//foo/bar'}
. Defaults tofalse
.
The url.parse()
method takes a URL string, parses it, and returns a URL
object.
A TypeError
is thrown if urlString
is not a string.
A URIError
is thrown if the auth
property is present but cannot be decoded.
url.resolve(from, to)#
The url.resolve()
method resolves a target URL relative to a base URL in a
manner similar to that of a Web browser resolving an anchor tag HREF.
For example:
const url = require('url');
url.resolve('/one/two/three', 'four'); // '/one/two/four'
url.resolve('http://example.com/', '/one'); // 'http://example.com/one'
url.resolve('http://example.com/one', '/two'); // 'http://example.com/two'
Percent-Encoding in URLs#
URLs are permitted to only contain a certain range of characters. Any character falling outside of that range must be encoded. How such characters are encoded, and which characters to encode depends entirely on where the character is located within the structure of the URL.
Legacy API#
Within the Legacy API, spaces (' '
) and the following characters will be
automatically escaped in the properties of URL objects:
< > " ` \r \n \t { } | \ ^ '
For example, the ASCII space character (' '
) is encoded as %20
. The ASCII
forward slash (/
) character is encoded as %3C
.
WHATWG API#
The WHATWG URL Standard uses a more selective and fine grained approach to selecting encoded characters than that used by the Legacy API.
The WHATWG algorithm defines three "percent-encode sets" that describe ranges of characters that must be percent-encoded:
The C0 control percent-encode set includes code points in range U+0000 to U+001F (inclusive) and all code points greater than U+007E.
The path percent-encode set includes the C0 control percent-encode set and code points U+0020, U+0022, U+0023, U+003C, U+003E, U+003F, U+0060, U+007B, and U+007D.
The userinfo encode set includes the path percent-encode set and code points U+002F, U+003A, U+003B, U+003D, U+0040, U+005B, U+005C, U+005D, U+005E, and U+007C.
The userinfo percent-encode set is used exclusively for username and passwords encoded within the URL. The path percent-encode set is used for the path of most URLs. The C0 control percent-encode set is used for all other cases, including URL fragments in particular, but also host and path under certain specific conditions.
When non-ASCII characters appear within a hostname, the hostname is encoded using the Punycode algorithm. Note, however, that a hostname may contain both Punycode encoded and percent-encoded characters. For example:
const { URL } = require('url');
const myURL = new URL('https://%CF%80.com/foo');
console.log(myURL.href);
// Prints https://xn--1xa.com/foo
console.log(myURL.origin);
// Prints https://π.com