window.location.indexOf not working in Javascript

问题

Below is what I have.

var myString = "http://localhost:8888/www.smart-kw.com/";
alert(myString.indexOf("localhost"));

This give me alert... however if I change var myString = "http://localhost:8888/www.smart-kw.com/"; to var myString = window.location;, it won't work (I don't get alert).

var myString = window.location;
alert(myString.indexOf("localhost"));

回答1:

window.location is an accessor property, and getting its value gives you an object, not a string, and so it doesn't have an indexOf function. (It's perfectly understandable that people sometimes think it's a string, since when you set its value, the accessor property's setter accepts a string; that is, window.location = "some url"; actually works. But when you get it, you don't get a string.)

You can use window.location.toString(), String(window.location), or window.location.href to get a string for it if you like, or use any of its various properties to check specifics. From the link, given example url http://www.example.com:80/search?q=devmo#test:

• hash: The part of the URL that follows the # symbol, including the # symbol. You can listen for the hashchange event to get notified of changes to the hash in supporting browsers.
  Example: #test
• host: The host name and port number.
  Example: www.example.com:80
• hostname: The host name (without the port number).
  Example: www.example.com
• href: The entire URL.
  Example: http://www.example.com:80/search?q=devmo#test
• pathname: The path (relative to the host).
  Example: /search
• port: The port number of the URL.
  Example: 80
• protocol: The protocol of the URL.
  Example: http:
• search: The part of the URL that follows the ? symbol, including the ? symbol.
  Example: ?q=devmo

For instance, for your quoted example, you might check window.location.hostname === "localhost".

回答2:

As far as I know window.location is a Location object.

For instance, window.location.href will give you the entire URL.

var url = window.location.href;
alert(url.indexOf("domain"));

But this kind of check is bound to trigger false-positives. You are better using window.location.hostname property which holds the host name part.

var hostname = window.location.hostname;
alert(hostname === "my.domain.com");

回答3:

I found a way to make this work:

(window.location.href).indexOf("localhost") > -1)

I actually use this for my projects as conditionals and it works just fine.

来源：https://stackoverflow.com/questions/13669472/window-location-indexof-not-working-in-javascript