Question

I want to create an object which is singleton per a string. For example when I call myObject("string1") it always returns the same object but different from myObject("string2").

Answer 1

try this

var MyObject = function(){
    var objs = {};

    return function(str){
        if( objs[str] ){
            return objs[str];
        }else{
            objs[str] = function(){
                //some code here
            };
            return objs[str];
        }
    };
}();