print_r() in javascript

print_r.js

function print_r(theObj) {
  var out = '';
  if(theObj.constructor == Array ||
     theObj.constructor == Object){
    out +="<ul>";
    for(var p in theObj){
      if(theObj[p].constructor == Array||
         theObj[p].constructor == Object){
		out +="<li>["+p+"] => "+typeof(theObj)+"</li>";
        out +="<ul>";
        out +=print_r(theObj[p]);
        out +="</ul>";
      } else {
	out +="<li>["+p+"] => "+theObj[p]+"</li>";
      }
    }
    out +="</ul>";
  }
  return out;
}