I come across singleton pattern, it's quite tricky to understand how to implement it, and I know some people would suggest to avoid it most of the time, so below is specific singleton variation that I find it easy to understand, but somehow I feel that this is not the best implementation of this pattern, can you guys suggest better form of this pattern.
var Foo = (function () {
var instance;
var _priVar = 2;
var log = function() {
console.log("Hello");
};
function Singleton(x, y) {
if (instance) {
return instance;
}
this.name = x;
this.age = y + _priVar;
this.log = log;
instance = this;
}
Singleton.getInstance = function () {
return instance || new Singleton();
}
return Singleton;
}());
and my goal is that when we do following
var a = new Foo("Bob", 24);
var b = new Foo();
var c = Foo();
var d = Foo.getInstance();
we will still get
a == b // true
a == c // true
a == d // true
a.name // 'Bob'
b.age // 26
c.log // 'Hello'
d.name // 'Bob'