Develop Reference

Replace the url parameter value using js

I have a URL like below.
something.com/TaskHandler/search.do?action=search&category=basic&page=1&sortBy=NAME&Ascending=true&showHiddenElements=false
I want to replace the value of parameter showHiddenElements to some new value.
for e.g. exising value in URL -> showHiddenElements=false
I want to change it through JavaScript to -> showHiddenElements=true
Please advise.
Edit:
showHiddenElements may not always be false. And In some cases it may not be available.

Use the URL Object:
const url = new URL('http://something.com/TaskHandler/search.do?action=search&category=basic&page=1&sortBy=NAME&Ascending=true&showHiddenElements=false');
url.searchParams.delete('showHiddenElements');
url.searchParams.append('showHiddenElements', true);
So you just delete the parameter and update it with the new one (not the most elegant)
Docs here: https://developer.mozilla.org/fr/docs/Web/API/URL

You could use String.replace for that:
var url = 'something.com/TaskHandler/search.do?action=search&category=basic&page=1&sortBy=NAME&Ascending=true&showHiddenElements=false';
newUrl = url.replace('showHiddenElements=false', 'showHiddenElements=true');
You could also do it fancy and use regex:
var url = 'something.com/TaskHandler/search.do?action=search&category=basic&page=1&sortBy=NAME&Ascending=true&showHiddenElements=false';
newUrl = url.replace(/showHiddenElements=false$/, 'showHiddenElements=true');
The regex would only match showHiddenElements=false if it's on the end of the URL
To see if it's available you could use regex too:
var url = 'something.com/TaskHandler/search.do?action=search&category=basic&page=1&sortBy=NAME&Ascending=true&showHiddenElements=false';
// If the url doesn't have a showHiddenElements=__any_word__
if (!url.match(/showHiddenElements=\w+/)) {
url = url + 'showHiddenElements=false';
}

var url = "something.com/TaskHandler/search.do?action=search&category=basic&page=1&sortBy=NAME&Ascending=true&showHiddenElements=false";
alert("Before: "+url);
url = url.replace("&showHiddenElements=false","&showHiddenElements=true");
alert("After: "+url);
//Console.log clips the end so we can't see the result :(

Maybe something liket this:
var loc = window.location.href;
var newLoc = loc.Replace('showHiddenElements=true', 'showHiddenElements=false')

A JavaScript Regular Expression should help if you are just treating the URL as a string.
var str = 'something.com/TaskHandler/search.do?action=search&category=basic&page=1&sortBy=NAME&Ascending=true&showHiddenElements=false';
var res = str.replace(/showHiddenElements/i, 'true');
console.log(res);

Single regexp to get page URL but exclude port number from a full URL

I'm trying to come up with a regexp to get the page URL from the full URL but exclude a possible port number from it. So far I came up with the following JS:
var res = url.match(/^.*\:\/\/(?:www2?.)?([^?#]+)/i);
if(res)
{
var pageURL = res[1];
console.log(pageURL);
}
If I call it for this:
var url = "http://www.example.com/php/page.php?what=sw#print";
I get the correct answer: example.com/php/page.php
But if I do:
var url = "http://www.example.com:80/php/page.php?what=sw#print";
I need it to return example.com/php/page.php instead of example.com:80/php/page.php.
I can remove it with the second regexp, but I was curious if I could do it with just one (for speed)?

You can modify your regex to this:
/^.*\:\/\/(?:www2?.)?([^/:]+)(?:[^:]*:\d+)?([^?#]+)/i
RegEx Demo
It will return 2 matches:
1: example.com
2: /php/page.php
as match[1] and match[2] respectively for both inputs that you can concatenate.
http://www.example.com/php/page.php?what=sw#print
OR
http://www.example.com:80/php/page.php?what=sw#print
Update: Here are performance results on jsperf.com that shows regex method is fastest is of all.

Keep it simple:
~ node
> "http://www.example.com:3000/php/page.php?what=sw#print".replace(/:\d+/, '');
'http://www.example.com/php/page.php?what=sw#print'
> "http://www.example.com/php/page.php?what=sw#print".replace(/:\d+/, '');
'http://www.example.com/php/page.php?what=sw#print'

Why would you use a regex at all?
EDIT:
As pointed out by #c00000fd: Because document might not be available and document.createElement is very slow compared to RegExp - see:
http://jsperf.com/url-parsing/5
http://jsperf.com/hostname-from-url
Nevertheless I will leave my original answer for reference.
ORIGINAL ANSWER:
Instead you could just use the Anchor element:
Fiddle:
http://jsfiddle.net/12qjqx7n/
JS:
var url = 'http://foo:bar#www.example.com:8080/php/page.php?what=sw#print'
var a = document.createElement('a');
a.href = url;
console.log(a.hash);
console.log(a.host);
console.log(a.hostname);
console.log(a.origin);
console.log(a.password);
console.log(a.pathname);
console.log(a.port);
console.log(a.protocol);
console.log(a.search);
console.log(a.username);
Additional information:
http://www.w3schools.com/jsref/dom_obj_anchor.asp

How about a group for matching the port, if present?
var url = "http://www.example.com:80/php/page.php?what=sw#print";
var res = url.match(/^.*\:\/\/(?:www2?.)?([^?#\/:]+)(\:\d+)?(\/[^?#]+)/i);
if(res)
{
var pageURL = res[1]+res[3];
console.log(res, pageURL);
}

Try
var url = "http://www.example.com:80/php/page.php?what=sw#print";
var res = url.split(/\w+:\/\/+\w+\.|:+\d+|\?.*/).join("");
var url = "http://www.example.com:80/php/page.php?what=sw#print";
var res = url.split(/\w+:\/\/+\w+\.|:+\d+|\?.*/).join("");
document.body.innerText = res;

You could use replace method to modify your original string or Url,
> var url = "http://www.example.com/php/page.php?what=sw#print";
undefined
> var url1 = "http://www.example.com:80/php/page.php?what=sw#print";
undefined
> url.replace(/^.*?:\/\/(?:www2?.)?([^/:]+)(?::\d+)?([^?#]+).*$/g, "$1$2")
'example.com/php/page.php'
> url1.replace(/^.*?:\/\/(?:www2?.)?([^/:]+)(?::\d+)?([^?#]+).*$/g, "$1$2")
'example.com/php/page.php'
DEMO

Remove hash from current page’s URL

I want to remove the hash, as well as anything after it, from a URL. For example, I might have:
http://example.com/#question_1
… which slides to question no. 1 to show an error message. When the user’s input then passes validation, I need to remove #question_1 from the current location.
I’ve tried all of these, but none of them has worked for me:
document.location.href.replace(location.hash, "");
window.location.hash.split('#')[0];
window.location.hash.substr(0, window.location.hash.indexOf('#'));
Note: I don’t just want to get the URL – I want to remove it from my address bar.

history.pushState("", document.title, window.location.href.replace(/\#(.+)/, '').replace(/http(s?)\:\/\/([^\/]+)/, '') )

Try this :use .split() to split string by # and then read first element in array using index 0
var url = 'http://example.com#question_1';
var urlWithoutHash = url.split('#')[0];
alert(urlWithoutHash );

Use split in javascript
var str = "http://example.com#question_1";
alert(str.split("#")[0]);

Try this way:
var currentPath = window.location.pathname;
var myUrl = currentPath.split("#")[0];
OR
var currentPath = window.location.href;
var myUrl = currentPath.split("#")[0];
Hope it helps.

This will clear the id selector from the uri
location.hash = '';

Use .split as shown :
var str = "http://example.com#question_1";
alert((str.split("#")[0]);
or use .substring() as shown :
var str = "http://example.com#question_1";
alert((str.substring(0,str.indexOf('#'))));

How do i match text after a specific character?

I have a url that looks like this:
http://mysite/#/12345
How do I retrieve the text using regex after the /#/ which is essentially a token that I would like to use elsewhere in my javascript application?
Thanks.

You don't need regex here, just String#substr using String#indexOf:
var s = 'http://mysite/#/12345';
var p ='/#/'; // search needle
var r= s.substr(s.indexOf(p) + p.length);
//=> 12345

Let the browser do it for you
var parser = document.createElement('a');
parser.href = "http://mysite/#/12345";
alert(parser.hash.substring(2)); //This is just to remove the #/ at the start of the string
JSFiddle: http://jsfiddle.net/gibble/uvhqa4yv/

Try with JavaScript String methods.
var str='http://mysite/#/12345';
alert(str.substring(str.lastIndexOf("/#/")+3));
You can try with String'smatch() method as well that uses regex expression.
Just get the matched group from index 1 that is captured by enclosing inside the parenthesis (...)
var str='http://mysite/#/12345';
alert(str.match(/\/#\/(.*)$/)[1]);

Using the browser to parse the URL and getting the hash would probably be most reliable and would work with any valid URL
var url = 'http://mysite/#/12345';
var ele = document.createElement('a');
ele.href = url;
var result = ele.hash.slice(2);
FIDDLE
or you can just split and pop it
var result = url.split('#/').pop();

FileName from url excluding querystring

I have a url :
http://www.xyz.com/a/test.jsp?a=b&c=d
How do I get test.jsp of it ?

This should do it:
var path = document.location.pathname,
file = path.substr(path.lastIndexOf('/'));
Reference: document.location, substr, lastIndexOf

I wont just show you the answer, but I'll give you direction to it. First... strip out everything after the "?" by using a string utility and location.href.status (that will give you the querystring). Then what you will be left with will be the URL; get everything after the last "/" (hint: lastindexof).

Use a regular expression.
var urlVal = 'http://www.xyz.com/a/test.jsp?a=b&c=d';
var result = /a\/(.*)\?/.exec(urlVal)[1]
the regex returns an array, use [1] to get the test.jsp

This method does not depend on pathname:
<script>
var url = 'http://www.xyz.com/a/test.jsp?a=b&c=d';
var file_with_parameters = url.substr(url.lastIndexOf('/') + 1);
var file = file_with_parameters.substr(0, file_with_parameters.lastIndexOf('?'));
// file now contains "test.jsp"
</script>

var your_link = "http://www.xyz.com/a/test.jsp?a=b&c=d";
// strip the query from the link
your_link = your_link.split("?");
your_link = your_link[0];
// get the the test.jsp or whatever is there
var the_part_you_want = your_link.substring(your_link.lastIndexOf("/")+1);

Try this:
/\/([^/]+)$/.exec(window.location.pathname)[1]