Question

Is there any Native Javascript Functions to check if html tag exists?

I mean :

 var tag = "div";
 alert(isValidTag(tag)) // true;
 alert(isValidTag("foo")) // false;

If there is no native function for that, I will keep my function :

function isValidTag(tagName) {
  var tags = ["div","span","a","link" ... "body"];
  for(var i=0, len = tags.length; i++ < len; ) {
    if(tags[i] == tagName) return true;
  }
  return false;
}

Answer 1

How about this:

tags = 'a b body...'.split(' ');
function isTag(tag) {
  return tags.indexOf(tag.trim().toLowerCase()) > -1;
}