gistfile1.js

function Template(string){
  this.string = string;
  this.render = function(){
    var args = Array.prototype.slice.call(arguments);
    if(args.length === 1 && typeof args[0] === 'object'){
      return this.string.replace(/{([^}]*)}/gm, function(match,key) { return args[0][key] });
    }
    return this.string.replace(/\{(\d+)\}/g, function(match, idx){ return args[idx] });
  }
}

var myTemplate = new Template("Hey {0} what the fuck are you doing to my {1}");
myTemplate.render("Joel", "bannana");
//"Hey Joel, what the fuck are you doing to my bannana"

var myTemplate = new Template({"Hey {name} what the fuck are you doing to my {fruit}")
myTemplate.render({name: "Joel", fruit: "banana"})