Node.js – How to access the GET parameters after “?” in Express

expressnode.jsquery-string

I know how to get the params for queries like this:

app.get('/sample/:id', routes.sample);

In this case, I can use req.params.id to get the parameter (e.g. 2 in /sample/2).

However, for url like /sample/2?color=red, how can I access the variable color?

I tried req.params.color but it didn't work.

Best Answer

So, after checking out the express reference, I found that req.query.color would return me the value I'm looking for.

req.params refers to items with a ':' in the URL and req.query refers to items associated with the '?'

Example:

GET /something?color1=red&color2=blue

Then in express, the handler:

app.get('/something', (req, res) => {
    req.query.color1 === 'red'  // true
    req.query.color2 === 'blue' // true
})

Related Solutions

Javascript – How to get query string values in JavaScript

Update: June-2021

For a specific case when you need all query params:

const urlSearchParams = new URLSearchParams(window.location.search);
const params = Object.fromEntries(urlSearchParams.entries());

Update: Sep-2018

You can use URLSearchParams which is simple and has decent (but not complete) browser support.

const urlParams = new URLSearchParams(window.location.search);
const myParam = urlParams.get('myParam');

Original

You don't need jQuery for that purpose. You can use just some pure JavaScript:

function getParameterByName(name, url = window.location.href) {
    name = name.replace(/[\[\]]/g, '\\$&');
    var regex = new RegExp('[?&]' + name + '(=([^&#]*)|&|#|$)'),
        results = regex.exec(url);
    if (!results) return null;
    if (!results[2]) return '';
    return decodeURIComponent(results[2].replace(/\+/g, ' '));
}

Usage:

// query string: ?foo=lorem&bar=&baz
var foo = getParameterByName('foo'); // "lorem"
var bar = getParameterByName('bar'); // "" (present with empty value)
var baz = getParameterByName('baz'); // "" (present with no value)
var qux = getParameterByName('qux'); // null (absent)

NOTE: If a parameter is present several times (?foo=lorem&foo=ipsum), you will get the first value (lorem). There is no standard about this and usages vary, see for example this question: Authoritative position of duplicate HTTP GET query keys.

NOTE: The function is case-sensitive. If you prefer case-insensitive parameter name, add 'i' modifier to RegExp

NOTE: If you're getting a no-useless-escape eslint error, you can replace name = name.replace(/[\[\]]/g, '\\$&'); with name = name.replace(/[[\]]/g, '\\$&').

This is an update based on the new URLSearchParams specs to achieve the same result more succinctly. See answer titled "URLSearchParams" below.

Node.js – How to get the path to the current script with Node.js

I found it after looking through the documentation again. What I was looking for were the __filename and __dirname module-level variables.

__filename is the file name of the current module. This is the resolved absolute path of the current module file. (ex:/home/kyle/some/dir/file.js)
__dirname is the directory name of the current module. (ex:/home/kyle/some/dir)

Best Answer

Related Solutions

Javascript – How to get query string values in JavaScript

Node.js – How to get the path to the current script with Node.js

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