How can you check for a #hash in a URL using JavaS

Question

I have some jQuery JavaScript code that I want to run only when there is a hash (#) anchor link in a URL. How can you check for this character using JavaScript? I need a simple catch-all test that would detect URLs like these:

• example.com/page.html#anchor
• example.com/page.html#anotheranchor

Basically something along the lines of:

if (thereIsAHashInTheUrl) {        
    do this;
} else {
    do this;
}

If anyone could point me in the right direction, that would be much appreciated.

Answer 1

...or there's a jquery selector:

$('a[href^="#"]')

Answer 2

Here's what you can do to periodically check for a change of hash, and then call a function to process the hash value.

var hash = false; 
checkHash();

function checkHash(){ 
    if(window.location.hash != hash) { 
        hash = window.location.hash; 
        processHash(hash); 
    } t=setTimeout("checkHash()",400); 
}

function processHash(hash){
    alert(hash);
}

Answer 3

Throwing this in here as a method for abstracting location properties from arbitrary URI-like strings. Although window.location instanceof Location is true, any attempt to invoke Location will tell you that it's an illegal constructor. You can still get to things like hash, query, protocol etc by setting your string as the href property of a DOM anchor element, which will then share all the address properties with window.location.

Simplest way of doing this is:

var a = document.createElement('a');
a.href = string;

string.hash;

For convenience, I wrote a little library that utilises this to replace the native Location constructor with one that will take strings and produce window.location-like objects: Location.js

Answer 4

Usually clicks go first than location changes, so after a click is a good idea to setTimeOut to get updated window.location.hash

$(".nav").click(function(){
    setTimeout(function(){
        updatedHash = location.hash
    },100);
});

or you can listen location with:

window.onhashchange = function(evt){
   updatedHash = "#" + evt.newURL.split("#")[1]
};

I wrote a jQuery plugin that does something like what you want to do.

It's a simple anchor router.

Answer 5

function getHash() {
  if (window.location.hash) {
    var hash = window.location.hash.substring(1);

    if (hash.length === 0) { 
      return false;
    } else { 
      return hash; 
    }
  } else { 
    return false; 
  }
}

Answer 6

$('#myanchor').click(function(){
    window.location.hash = "myanchor"; //set hash
    return false; //disables browser anchor jump behavior
});
$(window).bind('hashchange', function () { //detect hash change
    var hash = window.location.hash.slice(1); //hash to string (= "myanchor")
    //do sth here, hell yeah!
});

This will solve the problem ;)