# query-string [![Build Status](https://travis-ci.org/sindresorhus/query-string.svg?branch=master)](https://travis-ci.org/sindresorhus/query-string) > Parse and stringify URL [query strings](https://en.wikipedia.org/wiki/Query_string) ---

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--- ## 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, use version 5: `npm install query-string@5`. ## Usage ```js 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)`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/create) and thus does not have a `prototype`. #### decode Type: `boolean`
Default: `true` Decode the keys and values. URI components are decoded with [`decode-uri-component`](https://github.com/SamVerschueren/decode-uri-component). #### arrayFormat Type: `string`
Default: `'none'` Supports both `index` for an indexed array representation or `bracket` for a *bracketed* array representation. - `bracket`: stands for parsing correctly arrays with bracket representation on the query string, such as: ```js queryString.parse('foo[]=1&foo[]=2&foo[]=3', {arrayFormat: 'bracket'}); //=> foo: [1,2,3] ``` - `index`: stands for parsing taking the index into account, such as: ```js queryString.parse('foo[0]=1&foo[1]=2&foo[3]=3', {arrayFormat: 'index'}); //=> foo: [1,2,3] ``` - `none`: is the **default** option and removes any bracket representation, such as: ```js queryString.parse('foo=1&foo=2&foo=3'); //=> foo: [1,2,3] ``` ### .stringify(*object*, *[options]*) Stringify an object into a query string, sorting the keys. #### strict Type: `boolean`
Default: `true` Strictly encode URI components with [strict-uri-encode](https://github.com/kevva/strict-uri-encode). It uses [encodeURIComponent](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/encodeURIComponent) if set to false. You probably [don't care](https://github.com/sindresorhus/query-string/issues/42) about this option. #### encode Type: `boolean`
Default: `true` [URL encode](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/encodeURIComponent) the keys and values. #### arrayFormat Type: `string`
Default: `'none'` Supports both `index` for an indexed array representation or `bracket` for a *bracketed* array representation. - `bracket`: stands for parsing correctly arrays with bracket representation on the query string, such as: ```js queryString.stringify({foo: [1,2,3]}, {arrayFormat: 'bracket'}); // => foo[]=1&foo[]=2&foo[]=3 ``` - `index`: stands for parsing taking the index into account, such as: ```js queryString.stringify({foo: [1,2,3]}, {arrayFormat: 'index'}); // => foo[0]=1&foo[1]=2&foo[3]=3 ``` - `none`: is the __default__ option and removes any bracket representation, such as: ```js 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. ```js const order = ['c', 'a', 'b']; queryString.stringify({ a: 1, b: 2, c: 3}, { sort: (m, n) => order.indexOf(m) >= order.indexOf(n) }); // => 'c=3&a=1&b=2' ``` ```js queryString.stringify({ b: 1, c: 2, a: 3}, {sort: false}); // => 'c=3&a=1&b=2' ``` 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. ```js 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](https://github.com/visionmedia/node-querystring/issues). You're much better off just converting the object to a JSON string: ```js 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: ```js queryString.parse('likes=cake&name=bob&likes=icecream'); //=> {likes: ['cake', 'icecream'], name: 'bob'} queryString.stringify({color: ['taupe', 'chartreuse'], id: '515'}); //=> 'color=chartreuse&color=taupe&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: ```js queryString.stringify({foo: false}); //=> 'foo=false' queryString.stringify({foo: null}); //=> 'foo' queryString.stringify({foo: undefined}); //=> '' ``` ## License MIT © [Sindre Sorhus](https://sindresorhus.com)