[javascript] Using the GET parameter of a URL in JavaScript

From my programming archive:

function querystring(key) {
   var re=new RegExp('(?:\\?|&)'+key+'=(.*?)(?=&|$)','gi');
   var r=[], m;
   while ((m=re.exec(document.location.search)) != null) r[r.length]=m[1];
   return r;
}

If the value doesn't exist, an empty array is returned.
If the value exists, an array is return that has one item, the value.
If several values with the name exists, an array containing each value is returned.

Examples:

var param1var = querystring("param1")[0];

document.write(querystring("name"));

if (querystring('id')=='42') alert('We apoligize for the inconvenience.');

if (querystring('button').length>0) alert(querystring('info'));

Examples related to javascript

need to add a class to an element How to make a variable accessible outside a function? Hide Signs that Meteor.js was Used How to create a showdown.js markdown extension Please help me convert this script to a simple image slider Highlight Anchor Links when user manually scrolls? Summing radio input values How to execute an action before close metro app WinJS javascript, for loop defines a dynamic variable name Getting all files in directory with ajax

Examples related to url

What is the difference between URL parameters and query strings? Allow Access-Control-Allow-Origin header using HTML5 fetch API File URL "Not allowed to load local resource" in the Internet Browser Slack URL to open a channel from browser Getting absolute URLs using ASP.NET Core How do I load an HTTP URL with App Transport Security enabled in iOS 9? Adding form action in html in laravel React-router urls don't work when refreshing or writing manually URL for public Amazon S3 bucket How can I append a query parameter to an existing URL?

Examples related to get

Getting "TypeError: failed to fetch" when the request hasn't actually failed java, get set methods For Restful API, can GET method use json data? Swift GET request with parameters Sending a JSON to server and retrieving a JSON in return, without JQuery Retrofit and GET using parameters Correct way to pass multiple values for same parameter name in GET request How to download HTTP directory with all files and sub-directories as they appear on the online files/folders list? Curl and PHP - how can I pass a json through curl by PUT,POST,GET Making href (anchor tag) request POST instead of GET?