How can I create static variables in JavaScript?

General Discussions
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1

I’m trying to understand how to use JavaScript static variables. Is there a way to define variables that retain their values across function calls or are shared among instances of a class in JavaScript? How can I achieve this functionality?

2

Been working with JavaScript for over a decade now, and if you’re diving into javascript static variables, using static inside classes is probably the cleanest and most intuitive route.

class Counter {
  static count = 0;
  increment() {
    Counter.count++;
    return Counter.count;
  }
}

Here, count is a class-level variable, shared across all instances. No matter how many times you instantiate Counter, they all access the same static count. It’s like a shared memory space across all class instances—classic static behavior!"

3

Yeah, @prynka.chatterjee’s right—that class approach is super straightforward. But I’ve often needed javascript static variables outside of class-based structures. In those cases, closures are a lifesaver.

const counter = (function () {
  let count = 0;
  return function () {
    count++;
    return count;
  };
})();

With this setup, count is tucked away inside the closure—acting just like a static variable. Every call to counter() increases the same hidden value. It’s perfect when you need persistent state but don’t want to mess with globals or create a whole class structure.

4

Totally agree with both of you! But sometimes I prefer a third approach—attaching the variable directly to the function. Been using this for years in utility functions where setting up closures or classes feels overkill.

function myFunc() {
  myFunc.counter = (myFunc.counter || 0) + 1;
  return myFunc.counter;
}

Since functions in JS are objects, you can treat them like containers too. This pattern gives you that javascript static variables feel, with even less overhead. It’s a great mix of readability and control—especially in simpler scripts or utilities