Question

Supposedly I have an object called cache, and I’d like to have cache.a, cache.b, cache.c, …, literally every cache.whatever to use a predefined value VALUE as default, before I explicitly set them to something like cache.a = 'FOOBAR'. Is there anyway to achieve this?

Answer 1

You can do this like

function Cache(){
    this.GetValue = function(propertyName){
        if(!this[propertyName]){
            this[propertyName] = "Value";
        }
        return this[propertyName];
    }

    this.SetValue = function(propertyName, Value){
        this[propertyName] = Value;
    }
    return this;
}

Edited:

You can use it like…

var cache = new Cache();
alert(cache.GetValue("a")); // It will alert "Value"

var newValueOfA = "New Value";
cache.SetValue("a", newValueOfA);

alert(cache.GetValue("a")); // It will alert "New Value"