this Keyword in Different Contexts

class Counter {
  #count = 0;
  increment = () => {
    this.#count++;
    console.log(this.#count);
  };
}

It's faster than regular functions
It's required for private fields
It maintains this binding in callbacks
Arrow function maintains 'this' binding because: 1) It captures 'this' from the class constructor context, 2) Works correctly when used as callback or event handler, 3) Avoids need for manual binding, 4) Preserves access to private fields, 5) Common pattern in React class components, 6) Trade-off is that it creates a new function per instance.
It reduces memory usage