/**
* Escape special regexp chars
*/
function escapeForRegexp(str) {
  var specials = new RegExp("[.*+?|()[]{}\]", "g"); // .*+?|()[]{}
  return str.replace(specials, "\$&");
}
// test
var arr = [1,2,3,'str'];
for(var i = 0, n = arr.length; i < n; i++) {
	console.log(arr[i]);
	if(typeof arr[i] == 'string')
		alert(arr[i]);
}