var ToDo  = function(action) {
this.action = action;
};

ToDo.prototype.sayAction =function() {
console.log("I have to " + this.action);
};

var grace = new ToDo("learn to use the promises of JS")

var mistyblunch = new ToDo("sleep")

grace.sayAction() 
mistyblunch.sayAction()

/*for to know what is my action*/
console.log(grace.action)
console.log(mistyblunch.action)