Javascript : onHashchange Test

I'm trying to check if the browser supports onHashChange or not to hide some code from it if not, in this way:

if(window.onhashchange){
    ...code...
} else {
   ...other code...
}

I tried this too:

if(typeof window.onhashchange === "function"){
    alert("Supports");  
} else {
    alert("Doesn't Supports");  
}

As described on Quirksmode this shoul开发者_Python百科d work but if I do an alert for example in true state in Safari than alerts me but Safari is not supporting onHashChange :S

What's the problem with it? If I'm not on the right way how should I check it?

You can detect this event by using the in operator:

if ("onhashchange" in window) {
  //...
}

See also:

• onhashchange - MDC
• Detecting event support without browser sniffing
• Emulating onhashchange without setInterval

Be warned that you're better off using feature detection rather than existence inference (such as "onhashchange" in window).

@xkit explained to me a good feature test to work around the fact that although IE7 doesn't support onhashchange it would still return true for existence inference such as if("onhashchange" in window){/code/} when using IE7 Standard Document Mode in IE8.

What @xkit suggested was setting a flag (such as var isSet = true;) within a handler function for the onhashchange event. Then changing window.location.hash using JavaScript and see if the flag was set.

It's likely that the version of Safari that you're using has added support for the onhashchange event since the time that that Quirksmode article was written. Tests should still be valid; try it in other browsers you know not to support the event.

Edit: also, you should use the method described by @CMS instead, as the event will not contain a function by default; thus both of those tests will fail.

if (window.onhashchange !== undefined) alert('Supports onhashchange');