Search string in javascript using RegExp

Javascript String class dont have a method like contains to search keyword from string. but just use that way to search. It's performance feel good.

   var originalString="Something to search";
   //Create new RegExp object. if you dont use second parameter, 
   //search method is match case
   var keyword = new RegExp("text to search here","i");
   var result = originalString.search(keyword);//Return index of keyword you have search.
   // Otherwise return -1

Sample in google chrome console