Open external links in a new tab without jQuery

Question

What\'s the best way to open all external links (URLs that don\'t match the current domain) in a new tab using JavaScript, without using jQuery?

Here\'s the jQuery I

Answer 1

Pure JS:

function externalLinks() {
  for(var c = document.getElementsByTagName("a"), a = 0;a < c.length;a++) {
    var b = c[a];
    b.getAttribute("href") && b.hostname !== location.hostname && (b.target = "_blank")
  }
}
;
externalLinks();