query-string 
Parse and stringify URL query strings
Install
$ npm install query-string
This module targets Node.js 6 or later and the latest version of Chrome, Firefox, and Safari. If you want support for older browsers, or, if your project is using create-react-app v1, use version 5: npm install query-string@5.
Usage
const queryString = require('query-string');
console.log(location.search);
//=> '?foo=bar'
const parsed = queryString.parse(location.search);
console.log(parsed);
//=> {foo: 'bar'}
console.log(location.hash);
//=> '#token=bada55cafe'
const parsedHash = queryString.parse(location.hash);
console.log(parsedHash);
//=> {token: 'bada55cafe'}
parsed.foo = 'unicorn';
parsed.ilike = 'pizza';
const stringified = queryString.stringify(parsed);
//=> 'foo=unicorn&ilike=pizza'
location.search = stringified;
// note that `location.search` automatically prepends a question mark
console.log(location.search);
//=> '?foo=unicorn&ilike=pizza'API
.parse(string, options?)
Parse a query string into an object. Leading ? or # are ignored, so you can pass location.search or location.hash directly.
The returned object is created with Object.create(null) and thus does not have a prototype.
options
Type: object
decode
Type: boolean
Default: true
Decode the keys and values. URL components are decoded with decode-uri-component.
arrayFormat
Type: string
Default: 'none'
'bracket': Parse arrays with bracket representation:
queryString.parse('foo[]=1&foo[]=2&foo[]=3', {arrayFormat: 'bracket'});
//=> {foo: ['1', '2', '3']}'index': Parse arrays with index representation:
queryString.parse('foo[0]=1&foo[1]=2&foo[3]=3', {arrayFormat: 'index'});
//=> {foo: ['1', '2', '3']}'comma': Parse arrays with elements separated by comma:
queryString.parse('foo=1,2,3', {arrayFormat: 'comma'});
//=> {foo: ['1', '2', '3']}'none': Parse arrays with elements using duplicate keys:
queryString.parse('foo=1&foo=2&foo=3');
//=> {foo: ['1', '2', '3']}sort
Type: Function | boolean
Default: true
Supports both Function as a custom sorting function or false to disable sorting.
parseNumbers
Type: boolean
Default: false
queryString.parse('foo=1', {parseNumbers: true});
//=> {foo: 1}Parse the value as a number type instead of string type if it's a number.
parseBooleans
Type: boolean
Default: false
queryString.parse('foo=true', {parseBooleans: true});
//=> {foo: true}Parse the value as a boolean type instead of string type if it's a boolean.
.stringify(object, [options])
Stringify an object into a query string and sorting the keys.
options
Type: object
strict
Type: boolean
Default: true
Strictly encode URI components with strict-uri-encode. It uses encodeURIComponent if set to false. You probably don't care about this option.
encode
Type: boolean
Default: true
URL encode the keys and values.
arrayFormat
Type: string
Default: 'none'
'bracket': Serialize arrays using bracket representation:
queryString.stringify({foo: [1, 2, 3]}, {arrayFormat: 'bracket'});
//=> 'foo[]=1&foo[]=2&foo[]=3''index': Serialize arrays using index representation:
queryString.stringify({foo: [1, 2, 3]}, {arrayFormat: 'index'});
//=> 'foo[0]=1&foo[1]=2&foo[2]=3''comma': Serialize arrays by separating elements with comma:
queryString.stringify({foo: [1, 2, 3]}, {arrayFormat: 'comma'});
//=> 'foo=1,2,3''none': Serialize arrays by using duplicate keys:
queryString.stringify({foo: [1, 2, 3]});
//=> 'foo=1&foo=2&foo=3'sort
Type: Function | boolean
Supports both Function as a custom sorting function or false to disable sorting.
const order = ['c', 'a', 'b'];
queryString.stringify({a: 1, b: 2, c: 3}, {
sort: (a, b) => order.indexOf(a) - order.indexOf(b)
});
//=> 'c=3&a=1&b=2'queryString.stringify({b: 1, c: 2, a: 3}, {sort: false});
//=> 'b=1&c=2&a=3'If omitted, keys are sorted using Array#sort(), which means, converting them to strings and comparing strings in Unicode code point order.
.extract(string)
Extract a query string from a URL that can be passed into .parse().
.parseUrl(string, options?)
Extract the URL and the query string as an object.
The options are the same as for .parse().
Returns an object with a url and query property.
queryString.parseUrl('https://foo.bar?foo=bar');
//=> {url: 'https://foo.bar', query: {foo: 'bar'}}Nesting
This module intentionally doesn't support nesting as it's not spec'd and varies between implementations, which causes a lot of edge cases.
You're much better off just converting the object to a JSON string:
queryString.stringify({
foo: 'bar',
nested: JSON.stringify({
unicorn: 'cake'
})
});
//=> 'foo=bar&nested=%7B%22unicorn%22%3A%22cake%22%7D'However, there is support for multiple instances of the same key:
queryString.parse('likes=cake&name=bob&likes=icecream');
//=> {likes: ['cake', 'icecream'], name: 'bob'}
queryString.stringify({color: ['taupe', 'chartreuse'], id: '515'});
//=> 'color=taupe&color=chartreuse&id=515'Falsy values
Sometimes you want to unset a key, or maybe just make it present without assigning a value to it. Here is how falsy values are stringified:
queryString.stringify({foo: false});
//=> 'foo=false'
queryString.stringify({foo: null});
//=> 'foo'
queryString.stringify({foo: undefined});
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