freddiefujiwara的答案很好，但我也需要在ie中支持相对url。我想出了以下解决方案:

function getLocation(href) {
    var location = document.createElement("a");
    location.href = href;
    // IE doesn't populate all link properties when setting .href with a relative URL,
    // however .href will return an absolute URL which then can be used on itself
    // to populate these additional fields.
    if (location.host == "") {
      location.href = location.href;
    }
    return location;
};

现在使用它来获得所需的属性:

var a = getLocation('http://example.com/aa/bb/');
document.write(a.hostname);
document.write(a.pathname);

例子:

function getLocation(href) { var location = document.createElement("a"); location.href = href; // IE doesn't populate all link properties when setting .href with a relative URL, // however .href will return an absolute URL which then can be used on itself // to populate these additional fields. if (location.host == "") { location.href = location.href; } return location; }; var urlToParse = 'http://example.com/aa/bb/', a = getLocation(urlToParse); document.write('Absolute URL: ' + urlToParse); document.write('<br />'); document.write('Hostname: ' + a.hostname); document.write('<br />'); document.write('Pathname: ' + a.pathname);

function parseUrl(url) {
    var m = url.match(/^((?:([^:\/?#]+:)(?:\/\/))?((?:([^\/?#:]*):([^\/?#:]*)@)?([^\/?#:]*)(?::([^\/?#:]*))?))?([^?#]*)(\?[^#]*)?(#.*)?$/),
        r = {
            hash: m[10] || "",                   // #asd
            host: m[3] || "",                    // localhost:257
            hostname: m[6] || "",                // localhost
            href: m[0] || "",                    // http://username:password@localhost:257/deploy/?asd=asd#asd
            origin: m[1] || "",                  // http://username:password@localhost:257
            pathname: m[8] || (m[1] ? "/" : ""), // /deploy/
            port: m[7] || "",                    // 257
            protocol: m[2] || "",                // http:
            search: m[9] || "",                  // ?asd=asd
            username: m[4] || "",                // username
            password: m[5] || ""                 // password
        };
    if (r.protocol.length == 2) {
        r.protocol = "file:///" + r.protocol.toUpperCase();
        r.origin = r.protocol + "//" + r.host;
    }
    r.href = r.origin + r.pathname + r.search + r.hash;
    return r;
};
parseUrl("http://username:password@localhost:257/deploy/?asd=asd#asd");

它既适用于绝对url，也适用于相对url

var loc = window.location;  // => "http://example.com:3000/pathname/?search=test#hash"

返回当前turl。

如果你想传递你自己的字符串作为url(在IE11中不工作):

var loc = new URL("http://example.com:3000/pathname/?search=test#hash")

然后你可以这样解析它:

loc.protocol; // => "http:"
loc.host;     // => "example.com:3000"
loc.hostname; // => "example.com"
loc.port;     // => "3000"
loc.pathname; // => "/pathname/"
loc.hash;     // => "#hash"
loc.search;   // => "?search=test"

第一个答案的简单破解

var getLocation = function(href=window.location.href) {
    var l = document.createElement("a");
    l.href = href;
    return l;
};

即使没有参数，也可以使用它来计算当前的主机名 getLocation()。Hostname将给出当前主机名

那么简单的正则表达式呢?

url = "http://www.example.com/path/to/somwhere";
urlParts = /^(?:\w+\:\/\/)?([^\/]+)(.*)$/.exec(url);
hostname = urlParts[1]; // www.example.com
path = urlParts[2]; // /path/to/somwhere

js-uri(在谷歌Code上可用)接受字符串URL并从中解析URI对象:

var some_uri = new URI("http://www.example.com/foo/bar");

alert(some_uri.authority); // www.example.com
alert(some_uri);           // http://www.example.com/foo/bar

var blah      = new URI("blah");
var blah_full = blah.resolve(some_uri);
alert(blah_full);         // http://www.example.com/foo/blah