Accessing a common property in a factory function

Say I want to have a counter in a factory function that counts the number of objects that were made, I can do it as such:

function foo(){
    // Factory code
    this.counter = this.counter? this.counter + 1 : 1
    console.log(this.counter)
}

let a = foo(); // Logs 1 
let b = foo(); // Logs 2,
console.log(foo.counter) // undefined

What this shows, is that the counter property is being saved and edited on the foo function object. But foo.counter is undefined. So my question is:

Where is the property being saved and how can I access it?

>Solution :

You can add a static property to count

function foo(){
    // Factory code
    foo.counter = foo.counter? foo.counter + 1 : 1;
    console.log(foo.counter)
}

let a = foo();
let b = foo();
console.log(foo.counter)

static property to count.