Develop Reference

Rewrite URL Prefix Using Javascript / Jquery

I am retrieving some data from an external API using javascript, I'm then displaying this data on a HTML page.
Within this returned data is a URL, it's in the following format;
var url = https://img.evbuc.com/moreStuff
I need to rewrite this URL so that it's prefixed with www, like this;
var url = https://www.img.evbuc.com/moreStuff
I want to achieve this using either javascript or jquery.
How can I achieve this? An explanation of the correct code would be great too.

You don't need regex for this you can simply use URL api
let url = "https://img.evbuc.com/moreStuff"
let parsed = new URL(url)
parsed.host = parsed.host.startsWith('www.') ? parsed.host : "www."+ parsed.host
console.log(parsed)

You can use a regular expression to search and replace.
Following example also works with:
http://img.evbuc.com/moreStuff
//img.evbuc.com/moreStuff
https://img.evbuc.com/moreStuff//someMoreStuff
function prependUrl(url) {
return url.replace(/^([^\/]*)(\/\/)(.*)/, '$1//www.$3');
}
const urls = [
'https://img.evbuc.com/moreStuff',
'http://img.evbuc.com/moreStuff',
'//img.evbuc.com/moreStuff',
'https://img.evbuc.com/moreStuff//someMoreStuff'
];
urls.forEach((url) => console.log(`${ url } -> ${ prependUrl(url) }`));
The regular expression contains 3 capturing groups:
Select everything up to the first / (excluding)
Select the // (for protocol root)
Select the rest
The replacement value takes everything up to the first / (which may be an empty string as well)
Replace the // with //www.
Append the rest

If you want something that will work with any protocol, try this regex:
var url = "https://img.evbuc.com/moreStuff"
var new_url = url.replace(/^([a-zA-Z][a-zA-Z0-9\.\+\-]*):\/\//, "$1://www.")
console.log('new URL: ', new_url)

Simple string operations:
var url = 'https://img.evbuc.com/moreStuff'
var newUrl = url.split('//')[0] + '//www.' + url.split('//')[1]
console.log(newUrl)
and yet another way to do this is like this:
var url = 'https://img.evbuc.com/moreStuff'
var newUrl = url.replace('https://', 'https://www.')
console.log(newUrl)

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);

Check if URL has anything after second "/" using javascript / jquery

So I have a completely variable url:
www.whatever.com/something/pagename
I need something to happen on the homepage of the websites and not on any of the other pages. Sometimes the homepage has a "something" in the url and sometimes it doesn't, so I need to find out if "pagename" exists, whatever it may be.
all values in the url vary so i can't simply search for a string in the url..
Is this possible to do this using only JS / JQuery?
Thanks

Split is the solution:
var exampleURL = "www.whatever.com/something/pagename";
var pageName = exampleURL.split("/")[2];
console.log(pageName);
//OUT -> pagename

Split the URL and then check the length of the result.
var split_url = url.split('/');
if (split_url.length > 2) {
// URL is like www.whatever.com/something/pagename...
} else {
// URL is just www.whatever.com or www.whatever.com/something
}
Another way is with a regular expression that matches a URL with two slashes:
if (url.match(/\/.*\//)) {
// URL contains two slashes
} else {
// URL has at most one slash
}

You could do a regex check:
/^[^\/\s]*(\/\/)?[^\/\s]+\/[^\/\s]+[^\/]+\/[^\/\s]+$/.test('www.whatever.com/something/pagename')
demo:
https://regex101.com/r/vF1bH8/1

The question is not really clear, but to answer the title literally https://jsfiddle.net/jgfeymk1/
function after2ndFSlash(inpu){
var pieces = inpu.split('/');
var output = document.getElementById('output');
if(pieces.length>2){
output.innerHTML += 'true<br/>';
}
else{
output.innerHTML += 'false<br/>';
}
}

Assuming that url string has protocol included ... http(s):// ... you can pass it to href of an <a> element and access the pathname property
var url ='http://www.whatever.com/something/pagename'
var a = document.createElement('a');
a.href = url;
var pathParts = a.pathname.replace(/^\//,'').split('/');//["something","pagename"]
alert(pathParts[1]); //"pagename"

javascript for splitting url and removing last part

http://www.google.com/site!#656126.72367
In this url, how to split and remove the part from exclamatory mark when page loaded using JS.
I just want http://www.google.com/site

Use string replace method , match every character after ! with regular expression and replace with ""
var url = 'http://www.google.com/site!#656126.72367';
url = url.replace(/!.*/,"");

You could use:
var host = window.location.hostname; // will be www.google.com
var path = window.location.pathname; // will be /site
In the end, you will have:
var url = "http://" + host + path;
Note: you can also use window.location.protocol, which in this case is http::
var url = window.location.protocol + '//' + host + path;
Update: as suggested by Rajesh, the window.location object also has access to the hash:
var hash = window.location.hash; // will be 656126.72367
It might be useful to do a console.log(window.location) and see what's in there!
This method works even if the hash contains several ! or #

var url = 'http://www.google.com/site!#656126.72367';
url = url.substring(0, url.indexOf('!'));
document.write(url);
substring extracts the characters from a string, between two specified indices (in this case on the first occurence and then on !), and returns the new sub string.
jsFiddle demo

var url = "http://www.google.com/site!#656126.72367";
url = url.split('!')[0];
console.log(url);

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]