Question

I am looking for getters and setters functionality but cannot rely on __defineGetter__ and __defineSetter__ yet. So how does one maintain a function variable’s value between function calls?

I tried the obvious, but myvar is always undefined at the start of the function:

FNS.itemCache = function(val) {
    var myvar;
    if( !$.isArray(myvar)
        myvar = [];
    if( val === undefined)
        return myvar;
    .. // Other stuff that copies the array elements from one to another without
       // recreating the array itself.
};

I could always put another FNS._itemCache = [] just above the function, but is there a way to encapsulate the values in the function between calls?

Answer 1

An alternative way to set a private variable is by wrapping the function definition in an anonymous function:

(function(){
    var myvar;
    FNS.itemCache = function(val) {
        if( !$.isArray(myvar))
            myvar = [];
        if( typeof val == "undefined")
            return myvar;
        .. // Other stuff that copies the array elements from one to another without
           // recreating the array itself.
    };
})();

This way, myvar is defined in the scope of FNS.itemCache. Because of the anonymous function wrapper, the variable cannot be modified from elsewhere.