constructor

TempConstructor

function myClass(params){
    
    if(typeof params === 'undefined')params = {};
    if( !('someOtherParam' in params)params.someOtherParam = 'blah';//Neat way to set default params in stuff :)

    this.params = params; //bind params to this instance 

    this.set = function(){
         //Do your thing
         if(typeof this.params.callback === "function")this.params.callback();
    }

    this.clear = function(){

    }

}

var myClassAttributes = {
    callback : function(){

    },
    someOtherParam : 'some'//Just for concept on passing other parameters to a class
}

var firstInstance = new myClass(myClassAttributes);