I'd like to get the value after a hash in the URL of the current page and then be able to apply this in a new function... eg.
The URL could be
www.example.com/index.html#foo
And I would like to use this in conjunction with the following piece of code
$('ul#foo:first').show();
I'm kinda assuming/hoping there is some way of grabbing this, and turning it into a variable that I can then use in the second piece of code.
Editor's note: the approach below has serious security implications and, depending upon the version of jQuery you are using, may expose your users to XSS attacks. For more detail, see the discussion of the possible attack in the comments on this answer or this explanation on Security Stack Exchange.
You can use the location.hash property to grab the hash of the current page:
var hash = window.location.hash;
$('ul'+hash+':first').show();
Note that this property already contains the # symbol at the beginning.
Actually you don't need the :first pseudo-selector since you are using the ID selector, is assumed that IDs are unique within the DOM.
In case you want to get the hash from an URL string, you can use the String.substring method:
var url = "http://example.com/file.htm#foo";
var hash = url.substring(url.indexOf('#')); // '#foo'
Advice: Be aware that the user can change the hash as he wants, injecting anything to your selector, you should check the hash before using it.
var hash = location.hash.slice(1); $('ul.item'+hash).show().append($('#content')); this will execute a script tag put in the hash. It is a good habit to use $('body').find('ul'+hash+':first') instead of $('ul'+hash+':first').
var hash = location.hash.replace('#', '');
$(userInput) is generally unsafe because $ is overloaded and might either search for existing nodes or create new ones depending on whether the string contains <> characters. $(document).find(userInput) will always search for existing nodes so it is less unsafe. That said, the best practice is to always sanitize user input, e.g. if you use alphanumeric ids make sure it is alphanumeric.location.hash is not safe for IE , in case of IE ( including IE9 ) , if your page contains iframe , then after manual refresh inside iframe content get location.hash value is old( value for first page load ). while manual retrieved value is different than location.hash so always retrieve it through document.URL
var hash = document.URL.substr(document.URL.indexOf('#')+1)
For those who are looking for pure javascript solution
document.getElementById(location.hash.substring(1)).style.display = 'block'
Hope this saves you some time.
Since jQuery 1.9, the :target selector will match the URL hash. So you could do:
$(":target").show(); // or $("ul:target").show();
Which would select the element with the ID matching the hash and show it.
I'm using this to address the security implications noted in @CMS's answer.
// example 1: www.example.com/index.html#foo
// load correct subpage from URL hash if it exists
$(window).on('load', function () {
var hash = window.location.hash;
if (hash) {
hash = hash.replace('#',''); // strip the # at the beginning of the string
hash = hash.replace(/([^a-z0-9]+)/gi, '-'); // strip all non-alphanumeric characters
hash = '#' + hash; // hash now equals #foo with example 1
// do stuff with hash
$( 'ul' + hash + ':first' ).show();
// etc...
}
});
I would suggest better cek first if the current page has a hash. Otherwise it will be undefined.
$(window).on('load', function(){
if( location.hash && location.hash.length ) {
var hash = decodeURIComponent(location.hash.substr(1));
$('ul'+hash+':first').show();;
}
});
I found the marked answer wasn't sufficient for me. It states that getting the hash from the URL has huge security flaws but offers no real way of combatting it. There are ways out there of sanitizing the URL if you want to go that route, but if you're simply trying to show() a container, or apply some CSS/classes to the hash-matching ID container, then there's a much simpler way...
Introducing the :target selector.
The :target pseudo-class represents the unique element that has a matching id to the URL's fragment, meaning you can apply JS to it by simply doing something like:
$(':target').show();
Or in my case, just un-hiding the element I want with CSS only:
:target {
display: block;
}
I know the OP's answer is almost exactly 13 years old, but this is a significantly easier and more secure way of achieving the same effect without dealing with getting the URL, splitting it up, sanitizing it - and hell, you can even avoid JS altogether with this method.
And yes, the :target selector is well-supported
'ul#foo:first'doesn't make sense since IDs must be unique, therefore adding:firstto the selector is redundant, unless you're duplicating IDs which is invalid. Note that even a decade ago, repeated IDs were still invalid.