Test if links are external with jQuery / javascript?

Question

How do I test to see if links are external or internal? Please note:

1. I cannot hard code the local domain.
2. I cannot test for \"http\". I could just as

Answer 1

And the no-jQuery way

var nodes = document.getElementsByTagName("a"), i = nodes.length;
var regExp = new RegExp("//" + location.host + "($|/)");
while(i--){
    var href = nodes[i].href;
    var isLocal = (href.substring(0,4) === "http") ? regExp.test(href) : true;
    alert(href + " is " + (isLocal ? "local" : "not local"));
}

All hrefs not beginning with http (http://, https://) are automatically treated as local