The url module provides utilities for URL resolution and parsing. It can be
accessed using:
const url = require('url');
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.
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.example.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.
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.example.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 myURL =
new URL('https://user:pass@sub.example.com:8080/p/a/t/h?query=string#hash');
Parsing the URL string using the Legacy API:
const url = require('url');
const myURL =
url.parse('https://user:pass@sub.example.com:8080/p/a/t/h?query=string#hash');
Browser-compatible URL class, implemented by following the WHATWG URL
Standard. Examples of parsed URLs may be found in the Standard itself.
The URL class is also available on the global object.
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.
input input
is relative, then base is required. If input is absolute, the base
is ignored.base input is not
absolute.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 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 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 myURL = new URL('https://測試');
// https://xn--g6w251d/
This feature is only available if the node executable was compiled with
ICU enabled. If not, the domain names are passed through unchanged.
In cases where it is not known in advance if input is an absolute URL
and a base is provided, it is advised to validate that the origin of
the URL object is what is expected.
let myURL = new URL('http://Example.com/', 'https://example.org/');
// http://example.com/
myURL = new URL('https://Example.com/', 'https://example.org/');
// https://example.com/
myURL = new URL('foo://Example.com/', 'https://example.org/');
// foo://Example.com/
myURL = new URL('http:Example.com/', 'https://example.org/');
// http://example.com/
myURL = new URL('https:Example.com/', 'https://example.org/');
// https://example.org/Example.com/
myURL = new URL('foo:Example.com/', 'https://example.org/');
// foo:Example.com/
Gets and sets the fragment portion of the 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.
Gets and sets the host portion of the 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.
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 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.
Gets and sets the serialized 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.
Gets the read-only serialization of the URL's origin.
const myURL = new URL('https://example.org/foo/bar?baz');
console.log(myURL.origin);
// Prints https://example.org
const idnURL = new URL('https://測試');
console.log(idnURL.origin);
// Prints https://xn--g6w251d
console.log(idnURL.hostname);
// Prints xn--g6w251d
Gets and sets the password portion of the 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.
Gets and sets the path portion of the 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.
Gets and sets the port portion of the URL.
The port value may be a number or 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 ('').
The port value can be an empty string in which case the port depends on the protocol/scheme:
| protocol | port |
|---|---|
| "ftp" | 21 |
| "file" | |
| "gopher" | 70 |
| "http" | 80 |
| "https" | 443 |
| "ws" | 80 |
| "wss" | 443 |
Upon assigning a value to the port, the value will first be converted to a
string using .toString().
If that string is invalid but it begins with a number, the leading number is
assigned to port.
If the number lies outside the range denoted above, it is ignored.
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 which are not represented in scientific notation
// will be ignored.
myURL.port = 1e10; // 10000000000, will be range-checked as described below
console.log(myURL.port);
// Prints 1234
Note that numbers which contain a decimal point, such as floating-point numbers or numbers in scientific notation, are not an exception to this rule. Leading numbers up to the decimal point will be set as the URL's port, assuming they are valid:
myURL.port = 4.567e21;
console.log(myURL.port);
// Prints 4 (because it is the leading number in the string '4.567e21')
Gets and sets the protocol portion of the 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.
The WHATWG URL Standard considers a handful of URL protocol schemes to be
special in terms of how they are parsed and serialized. When a URL is
parsed using one of these special protocols, the url.protocol property
may be changed to another special protocol but cannot be changed to a
non-special protocol, and vice versa.
For instance, changing from http to https works:
const u = new URL('http://example.org');
u.protocol = 'https';
console.log(u.href);
// https://example.org
However, changing from http to a hypothetical fish protocol does not
because the new protocol is not special.
const u = new URL('http://example.org');
u.protocol = 'fish';
console.log(u.href);
// http://example.org
Likewise, changing from a non-special protocol to a special protocol is also not permitted:
const u = new URL('fish://example.org');
u.protocol = 'http';
console.log(u.href);
// fish://example.org
The protocol schemes considered to be special by the WHATWG URL Standard
include: ftp, file, gopher, http, https, ws, and wss.
Gets and sets the serialized query portion of the 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.
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.
Gets and sets the username portion of the 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.
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.
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 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/"]
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 URLSearchParams class is also available on the global object.
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 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
Instantiate a new empty URLSearchParams object.
Parse the string as a query string, and use it to instantiate a new
URLSearchParams object. A leading '?', if present, is ignored.
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'
Instantiate a new URLSearchParams object with a query hash map. The key and
value of each property of obj are always coerced to strings.
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 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'
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.
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
Append a new name-value pair to the query string.
Remove all name-value pairs whose name is name.
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]().
fn thisArg To be used as this value for when fn is calledIterates over each name-value pair in the query and invokes the given function.
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
Returns the value of the first name-value pair whose name is name. If there
are no such pairs, null is returned.
Returns the values of all name-value pairs whose name is name. If there are
no such pairs, an empty array is returned.
Returns true if there is at least one name-value pair whose name is name.
Returns an ES6 Iterator over the names of each name-value pair.
const params = new URLSearchParams('foo=bar&foo=baz');
for (const name of params.keys()) {
console.log(name);
}
// Prints:
// foo
// foo
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 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
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 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
Returns the search parameters serialized as a string, with characters percent-encoded where necessary.
Returns an ES6 Iterator over the values of each name-value pair.
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 params = new URLSearchParams('foo=bar&xyz=baz');
for (const [name, value] of params) {
console.log(name, value);
}
// Prints:
// foo bar
// xyz baz
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
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 This function ensures the correct decodings of percent-encoded characters as well as ensuring a cross-platform valid absolute path string.
new URL('file:///C:/path/').pathname; // Incorrect: /C:/path/
fileURLToPath('file:///C:/path/'); // Correct: C:\path\ (Windows)
new URL('file://nas/foo.txt').pathname; // Incorrect: /foo.txt
fileURLToPath('file://nas/foo.txt'); // Correct: \nas\foo.txt (Windows)
new URL('file:///你好.txt').pathname; // Incorrect: /%E4%BD%A0%E5%A5%BD.txt
fileURLToPath('file:///你好.txt'); // Correct: /你好.txt (POSIX)
new URL('file:///hello world').pathname; // Incorrect: /hello%20world
fileURLToPath('file:///hello world'); // Correct: /hello world (POSIX)
URL auth true if the serialized URL string should include the
username and password, false otherwise. Default: true.fragment true if the serialized URL string should include the
fragment, false otherwise. Default: true.search true if the serialized URL string should include the
search query, false otherwise. Default: true.unicode true if Unicode characters appearing in the host
component of the URL string should be encoded directly as opposed to being
Punycode encoded. Default: false.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.
const myURL = new URL('https://a:b@測試?abc#foo');
console.log(myURL.href);
// Prints https://a:b@xn--g6w251d/?abc#foo
console.log(myURL.toString());
// Prints https://a:b@xn--g6w251d/?abc#foo
console.log(url.format(myURL, { fragment: false, unicode: true, auth: false }));
// Prints 'https://測試/?abc'
This function ensures that path is resolved absolutely, and that the URL
control characters are correctly encoded when converting into a File URL.
new URL(__filename); // Incorrect: throws (POSIX)
new URL(__filename); // Incorrect: C:\... (Windows)
pathToFileURL(__filename); // Correct: file:///... (POSIX)
pathToFileURL(__filename); // Correct: file:///C:/... (Windows)
new URL('/foo#1', 'file:'); // Incorrect: file:///foo#1
pathToFileURL('/foo#1'); // Correct: file:///foo%231 (POSIX)
new URL('/some/path%.js', 'file:'); // Incorrect: file:///some/path%
pathToFileURL('/some/path%.js'); // Correct: file:///some/path%25 (POSIX)
The legacy urlObject (require('url').Url) is created and returned by the
url.parse() function.
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 @.
The string is either the username, or it is the username and password separated
by :.
For example: 'user:pass'.
The hash property is the fragment identifier portion of the URL including the
leading # character.
For example: '#hash'.
The host property is the full lower-cased host portion of the URL, including
the port if specified.
For example: 'sub.example.com:8080'.
The hostname property is the lower-cased host name portion of the host
component without the port included.
For example: 'sub.example.com'.
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.example.com:8080/p/a/t/h?query=string#hash'.
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.
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.
The port property is the numeric port portion of the host component.
For example: '8080'.
The protocol property identifies the URL's lower-cased protocol scheme.
For example: 'http:'.
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.
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.
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.
urlObject | url.parse() or
constructed otherwise). If a string, it is converted to an object by passing
it to url.parse().The url.format() method returns a formatted URL string derived from
urlObject.
url.format({
protocol: 'https',
hostname: 'example.com',
pathname: '/some/path',
query: {
page: 1,
format: 'json'
}
});
// => 'https://example.com/some/path?page=1&format=json'
If urlObject is not an object or a string, url.format() will throw a
TypeError.
The formatting process operates as follows:
result is created.urlObject.protocol is a string, it is appended as-is to result.urlObject.protocol is not undefined and is not a string, an
Error is thrown.urlObject.protocol that do not end with an ASCII
colon (:) character, the literal string : will be appended to result.If either of the following conditions is true, then the literal string //
will be appended to result:
urlObject.slashes property is true;urlObject.protocol begins with http, https, ftp, gopher, or
file;urlObject.auth property is truthy, and either
urlObject.host or urlObject.hostname are not undefined, the value of
urlObject.auth will be coerced into a string and appended to result
followed by the literal string @.If the urlObject.host property is undefined then:
urlObject.hostname is a string, it is appended to result.urlObject.hostname is not undefined and is not a string,
an Error is thrown.If the urlObject.port property value is truthy, and urlObject.hostname
is not undefined:
: is appended to result, andurlObject.port is coerced to a string and appended to
result.urlObject.host property value is truthy, the value of
urlObject.host is coerced to a string and appended to result.If the urlObject.pathname property is a string that is not an empty string:
urlObject.pathname does not start with an ASCII forward slash
(/), then the literal string '/' is appended to result.urlObject.pathname is appended to result.urlObject.pathname is not undefined and is not a string, an
Error is thrown.urlObject.search property is undefined and if the urlObject.query
property is an Object, the literal string ? is appended to result
followed by the output of calling the querystring module's stringify()
method passing the value of urlObject.query.Otherwise, if urlObject.search is a string:
urlObject.search does not start with the ASCII question
mark (?) character, the literal string ? is appended to result.urlObject.search is appended to result.urlObject.search is not undefined and is not a string, an
Error is thrown.If the urlObject.hash property is a string:
urlObject.hash does not start with the ASCII hash (#)
character, the literal string # is appended to result.urlObject.hash is appended to result.urlObject.hash property is not undefined and is not a
string, an Error is thrown.result is returned.urlString parseQueryString true, the query property will always
be set to an object returned by the querystring module's parse()
method. If false, the query property on the returned URL object will be an
unparsed, undecoded string. Default: false.slashesDenoteHost true, the first token after the literal
string // and preceding the next / will be interpreted as the host.
For instance, given //foo/bar, the result would be
{host: 'foo', pathname: '/bar'} rather than {pathname: '//foo/bar'}.
Default: false.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.
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.
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'
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.
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.
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 four "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 fragment percent-encode set includes the C0 control percent-encode set and code points U+0020, U+0022, U+003C, U+003E, and U+0060.
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 fragment percent-encode set is used for URL fragments. The C0 control percent-encode set is used for host and path under certain specific conditions, in addition to all other cases.
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:
const myURL = new URL('https://%CF%80.example.com/foo');
console.log(myURL.href);
// Prints https://xn--1xa.example.com/foo
console.log(myURL.origin);
// Prints https://xn--1xa.example.com